Method for controlling a brake system and brake system

Abstract

The invention relates to a method for controlling a brake system. The invention aims to further improve the fault safety of the brake system. The method comprises the steps of transmitting pedal sensor data indicative of a pedal operation of the electronic brake pedal to a brake control unit, calculating, by the brake control unit, pre-processed data, transmitting, by the brake control unit, the pre-processed data to a vehicle regulator of the motor vehicle, calculating control information for the at least one electromechanical wheel brake in the vehicle regulator from the pre-processed data, transmitting the control information to the brake control unit; before forwarding the control information to the wheel brake, it is determined by the at least one brake control unit whether the control information received from the vehicle regulator is below a safety threshold, in which case the control information is covered before forwarding to the at least one electromechanical wheel brake. The invention also relates to a brake system configured to carry out the method.

Description

Technical Field

[0001] This invention relates to a method for controlling a braking system, specifically comprising an electronic brake pedal, a brake control unit, and a vehicle adjuster for controlling at least one electromechanical brake. The invention also relates to a braking system configured to perform this method. Background Technology

[0002] DE 10 2022 209 930 A1 has disclosed such a braking system.

[0003] A subsequently published German patent application, application number 10 2023 200 166.7, discloses an EMB system architecture (EMB = Electromechanical Brake) that enables the implementation of a dual-loop backup / redundancy scheme. Its fundamental prerequisite is the use of a redundant electronic brake pedal, where two independent sensor paths are supplied to two equally independent electronic control units (ECUs). The patent application proposes two axle control units (AxCUs, i.e., control units for regulating the electromechanical wheel brakes of the vehicle axles) for processing the redundant sensor paths. These two control units process the sensor signals from the electronic brake pedal, for example, by reading them from the sensor interface according to the SENT standard, performing preprocessing, monitoring, and possible rationality checks, and providing signals regulated in this manner on the communication bus(s). Therefore, information regarding the degree of brake pedal operation reaches the vehicle regulator, which again calculates the braking request from this information in the form of braking force or vehicle deceleration, distributes the braking force to the four wheel brakes of the vehicle, and sends the corresponding target value to the control unit of the electromechanical wheel brakes.

[0004] In the event of a complete failure of the vehicle regulator, the calculation and execution of the driver's braking request requires at least one level of redundancy. This has been established by relevant standards that specify the minimum deceleration capability in the event of a single failure in the braking system. Summary of the Invention

[0005] Therefore, the object of this invention is to further improve the fail-safety of braking systems, particularly in the event of interference / faults that were previously undetected in the vehicle regulator. This specifically relates to situations where the vehicle regulator is not completely faulty, meaning that control information can still be supplied, but this control information may be erroneous. This could be caused by hardware failure or software error. Such partial functional failures are more difficult to detect than complete failures; therefore, existing safety measures and backup systems are insufficient to cover or can only partially cover such partial functional failures.

[0006] According to the present invention, this objective is achieved by the method as claimed in claim 1 and the braking system as claimed in claim 8.

[0007] Preferred embodiments and improvements of the present invention can be derived from the corresponding dependent claims.

[0008] The objective of the present invention is achieved by a method for controlling a braking system, the method comprising the following steps:

[0009] - Pedal sensor data indicating pedal operation of the electronic brake pedal is transmitted from at least one pedal sensor of the brake pedal to at least one brake control unit.

[0010] - The preprocessed data is calculated by the at least one brake control unit.

[0011] - The preprocessed data is transmitted to the vehicle regulator of the motor vehicle via a signal link by at least one brake control unit.

[0012] - The vehicle regulator calculates control information for at least one electromechanical wheel brake based on preprocessed data.

[0013] - The control information for the at least one electromechanical wheel brake is transmitted to at least one brake control unit.

[0014] Before forwarding control information to the at least one electromechanical wheel brake, the at least one brake control unit determines whether the control information received from the vehicle regulator is below a safety threshold. If the control information is below the safety threshold, the control information is overridden before forwarding it to the at least one electromechanical wheel brake. This makes it possible to specifically avoid safety-related under-braking caused by incorrect control information from the vehicle regulator. Simultaneously, the specific braking behavior during normal operation can be specifically adapted to the vehicle regulator of the respective automaker, and the brake control unit overwrites the control information only when safety-related under-braking is detected. Due to the sequence of signal forwarding and processing, the at least one brake control unit is aware of the pedal sensor data and can therefore detect whether a safety-related error has occurred in the calculation of the control information in the vehicle regulator by comparing the pedal sensor data or pre-processed data with the control information. A particular advantage of the method according to the invention is that it can intervene both in the event of a complete failure of the vehicle regulator and in the event of a short-term or continuous failure of the vehicle regulator, without knowing or identifying the exact cause.

[0015] The braking system includes at least one electromechanical wheel brake, but may also include two, three, or four electromechanical wheel brakes. Preferably, in the steps of the method according to the invention, control information is calculated and / or forwarded and / or overridden by a vehicle regulator and / or brake control unit for all existing wheel brakes, in their respective cases.

[0016] Advantageously, the safety threshold is defined by a characteristic curve associated with the pedal sensor data, wherein the characteristic curve is stored locally in the at least one brake control unit. The characteristic curve may be stored in the brake control unit (or these) as a lookup table or as a functional relationship, for example.

[0017] In one embodiment, the at least one brake control unit automatically calculates secondary control information from pedal sensor data, and uses this secondary control information to override the control information received from the vehicle regulator if a safety threshold is lowered. This has the advantage that if the control information from the vehicle regulator is lower than the safety threshold, the brake control unit can respond more quickly because the secondary control information has already been calculated in parallel with the vehicle regulator and is available immediately, without requiring further local calculation steps.

[0018] Preferably, at least one method step is executed in parallel in two brake control units. Particularly preferably, all steps of the method according to the invention related to the brake control units are executed in parallel in two brake control units, but at the end of the method, only one brake control unit transmits unchanged or overridden control information to the wheel brakes. This allows the brake control units to check the validity of preprocessed data and / or control information from each other, or for the other brake control unit to take over at any time in the event of a failure in one brake control unit.

[0019] In one embodiment, the safety threshold is determined based on a deceleration characteristic curve related to pedal sensor data, particularly related to pedal force. The safety threshold is lower than the deceleration characteristic curve by a constant deceleration value, for example, between 0.4 and 0.8 standard gravitational accelerations. However, the safety threshold is preferably always at least 0 m / s². 2 This ensures that the brake control unit will not intervene and the control information will not be overwritten when the deviation between the control information sent from the vehicle regulator to the brake control unit and the deceleration characteristic curve is relatively small. However, it also ensures that the brake control unit will always intervene when a braking request has been detected from the pedal sensor data but the vehicle regulator has not implemented any deceleration in the control information (e.g., due to software or memory errors).

[0020] Preferably, if the safety threshold is lowered, the overriding of control information continues until...

[0021] - New control information from the vehicle regulator is again above the safety threshold, or

[0022] - This indicates the end of the current braking process or the start of a new braking process, or

[0023] - This determines the end of the vehicle's current driving cycle or the start of a new driving cycle. A safety threshold is set below a minimum duration, which can be a one-time event or a continuous period. After this minimum duration, the brake control unit overwrites the vehicle regulator's control information for the electromechanical brakes for the aforementioned duration (i.e., switches to "overwrite mode").

[0024] Preferably, the control information received from the vehicle regulator is overridden only before being forwarded to the electromechanical wheel brakes if it remains below a safety threshold for a predetermined minimum duration, for example, 25 to 250 milliseconds. Appropriately selecting the minimum duration reduces the probability of undesirable accidental triggering of the "overriding mode," specifically preventing the brake control unit from taking over due to a single excessively low value in the control information from the vehicle regulator. Simultaneously, the minimum duration should not be selected too high to ensure that the brake control unit can still intervene quickly in emergency braking situations where the vehicle controller partially fails.

[0025] The present invention also relates to a braking system, particularly a braking system for a motor vehicle, the braking system comprising:

[0026] A brake pedal having at least one pedal sensor for obtaining a driver's braking request by means of pedal sensor data;

[0027] At least one electromechanical wheel brake, preferably four electromechanical wheel brakes;

[0028] At least one brake control unit, preferably two brake control units; and

[0029] Vehicle regulator of motor vehicles,

[0030] The brake control unit is configured to calculate preprocessed data from pedal sensor data and provide the preprocessed data to the vehicle regulator via a signal link.

[0031] The vehicle regulator is configured to calculate control information for at least one electromechanical wheel brake based on preprocessed data, and transmit the control information to the at least one wheel brake via at least one signal link.

[0032] At least one brake control unit is configured to perform the method as described in any one of the preceding claims. This braking system is particularly well protected against partial failure or malfunction in the vehicle regulator.

[0033] Preferably, the braking system includes two braking control units, each configured to perform the method as described in any one of the preceding claims. This further improves the fail-safety of the braking system.

[0034] In one embodiment, the braking system includes at least two primary wheel braking modules, each designed to be mounted on a wheel. Each primary wheel braking module integrates one electromechanical wheel brake and a corresponding associated brake control unit. Compared to separate redundant brake control units, the integration of the corresponding electromechanical wheel brake and its associated brake control unit into the primary wheel braking modules reduces installation costs while maintaining a high degree of fail-safety in the braking system.

[0035] Preferably, each pedal sensor is connected to one of the two brake control units via a separate brake request signal line. This configuration enables a high degree of fail-safety because the at least one pedal sensor is connected to the two brake control units via independent brake request signal lines.

[0036] The terms “signal line” and “signal link” are used synonymously in this document.

[0037] In one embodiment, the brake pedal includes at least two pedal sensors that determine different measurement variables, particularly a force sensor and / or a travel sensor and / or an angle sensor, wherein signals from at least two pedal sensors that determine different measurement variables can be transmitted to each brake control unit during operation. Using pedal sensors that determine different measurement variables improves fail-safety and, depending on the combination of measurement data, also partially improves the accuracy of brake request acquisition.

[0038] Particularly preferably, the brake pedal includes at least two redundant pedal sensors that determine the same measured variable, particularly two force sensors and / or two travel sensors and / or two angle sensors, and signals from each redundant pedal sensor can be transmitted to a corresponding brake control unit during operation. The pedal sensors determining the same measured variable are preferably pedal sensors with different designs and / or different measurement principles for the same measured variable. The brake pedal preferably includes at least four pedal sensors, wherein at least two corresponding pedal sensors each determine the same measured variable, i.e., for example, two force sensors and two travel sensors. Alternatively, two pedal sensors each determining three different measured variables can also be used, i.e., for example, two force sensors, two travel sensors, and two angle sensors. Thus, signals from two (or three) pedal sensors determining different measured variables can be transmitted to each brake control unit by different pedal sensors during operation. Each brake control unit is thus assigned its own set of pedal sensors that determine different measured variables. Each of the aforementioned features improves the fail-safety of the braking system.

[0039] In one embodiment, two primary wheel brake modules are assigned to one axle of the vehicle, and at least one basic control unit is assigned to two additional electromechanical wheel brakes on the other axle of the vehicle, and is designed to receive control information and control at least one of the additional electromechanical wheel brakes. Preferably, the basic control unit is not configured to calculate preprocessed data from pedal sensor data. Therefore, the basic control unit can be a significantly simpler control unit than the brake control unit, and can be designed correspondingly more cost-effectively.

[0040] Preferably, at least one basic control unit can be supplied with control information via separate signal lines from two brake control units during operation. As a result, during normal operation, the brake control unit can be connected in the signal path between the vehicle regulator and the basic control unit, allowing the brake control unit to perform monitoring functions via the vehicle regulator. In this way, incorrect control information can be identified by the brake control unit before it is implemented.

[0041] The braking system preferably includes two secondary wheel braking modules, each designed to be mounted on one wheel. Each of the two secondary wheel braking modules integrates one of the additional electromechanical wheel brakes and a corresponding assigned basic control unit. Each of the basic control units is designed to receive control information and control its assigned electromechanical wheel brake. Thus, by arranging wheel braking modules including an electromechanical wheel brake and a wheel control unit (WCU) on each wheel, the fail-safety of the braking system is improved without significantly increasing installation costs.

[0042] Preferably, the two basic control units can be supplied with control information via separate signal lines by the two brake control units during operation. As a result, in the event of a failure in one of the signal lines, the brake control unit connected to the other signal line can send control information to both basic control units (and optionally another brake control unit or its assigned wheel brakes).

[0043] The vehicle regulator is preferably configured to transmit control information for at least one electromechanical wheel brake to two brake control units via signal lines, preferably via two separate signal lines. Preferably, each brake control unit is configured to forward the control information to at least one electromechanical wheel brake, particularly to four electromechanical wheel brakes. Due to this type of signal distribution of the control information, at least one brake control unit can check the control information for one or more (e.g., four) wheel brakes before the control information from the vehicle regulator is implemented. This makes it possible to detect faults, software errors, and partial faults in the vehicle regulator that could otherwise cause braking failure. Previous safety measures and backup systems typically focused on complete hardware failures that are easier to detect automatically; however, with the increasing software control of vehicles, safety measures regarding software faults are becoming increasingly important.

[0044] Further details of the invention can be derived from the description of the embodiments and the appended claims. Attached Figure Description

[0045] In the attached diagram:

[0046] Figure 1 and Figure 2 A braking system with a basic control unit according to the present invention is shown.

[0047] Figure 3 and Figure 4 A braking system with two secondary wheel braking modules according to the present invention is shown.

[0048] Figure 5A flowchart of the method according to the present invention is shown.

[0049] Figure 6 The possible characteristic curves related to the pedal sensor data are shown. Detailed Implementation

[0050] In the following detailed description of preferred embodiments, the same reference numerals denote components that are substantially the same or identical in these embodiments. However, for the purpose of better illustrating the invention, the preferred embodiments shown in the drawings are not always illustrated to scale.

[0051] Figures 1 to 4 An embodiment of a braking system 1 for a motor vehicle according to the present invention is shown. The braking system includes a brake pedal 2 having at least two pedal sensors 3 and 4 for obtaining a driver's braking request by means of pedal sensor data. Furthermore, the braking system 1 includes four electromechanical wheel brakes 5, 6, 7, and 8 and two brake control units 9 and 10.

[0052] Each brake control unit 9, 10 is configured to calculate preprocessed data from pedal sensor data and provide the preprocessed data to the vehicle regulator 11 via signal links 12, 13, 14. Signal link 12 may be a vehicle bus (e.g., CAN bus) (see...). Figure 1 and Figure 3 Alternatively, the signal links 13 and 14 between the vehicle regulator 11 and the brake control units 9 and 10 can be separate signal lines (see [link]). Figure 2 and Figure 4 The vehicle regulator 11 can be configured to perform vehicle chassis functions 11A (e.g., control functions for the braking system 1), which is preferably performed by means of correspondingly configured software.

[0053] Pedal sensors 3 and 4 are each connected to two brake control units 9 and 10 via separate brake request signal lines 15 and 16.

[0054] The vehicle regulator 11 is configured to calculate control information for all electromechanical wheel brakes 5, 6, 7, 8 based on preprocessed data, and transmit the control information to the wheel brakes via at least one signal link 12, 13, 14. Brake control units 9 and 10 are each assigned to a brake circuit 17 and 18, and can independently supply control information to all electromechanical wheel brakes 5, 6, 7, 8 in the event of a failure of the vehicle regulator 11 and / or the corresponding other brake control unit 9 or 10.

[0055] Each brake control unit 9, 10 is configured to forward control information (from vehicle regulator 11 or its own backup level) to the four electromechanical wheel brakes 5, 6, 7, 8.

[0056] Therefore, the braking system architecture proposed according to the present invention is suitable for implementing a dual-circuit backup stage (via braking circuits 17, 18). This should be understood as follows: the two braking control units 9, 10 that process sensor data from the electronic brake pedal 2 not only have sensor signal preprocessing functions, but also have their own ability to acquire braking requests, and can also perform (typically conservative, i.e., stable) braking force distribution. Therefore, there are dual redundant paths for controlling the electromechanical wheel brakes 5, 6, 7, 8. These redundant paths can activate in the event of a fault (e.g., a fault in the vehicle regulator 11, a fault in the vehicle electrical system, or a fault in one of the braking control units 9, 10 of the electromechanical wheel brakes 5, 6, 7, 8).

[0057] This invention proposes connecting the redundant sensor path of the electronic brake pedal 2 (particularly via separate brake request signal lines 15, 16) to two separate brake control units 9, 10 of the electromechanical wheel brakes 5, 6, 7, 8 (particularly the electromechanical wheel brakes of the axle (e.g., the front axle). The link from the brake pedal 2 to the wheel control unit of the electromechanical wheel brakes 7, 8 of the rear axle is not shown in the figures, but this is equally possible.

[0058] A diagonal allocation (i.e., connecting one of the two redundant sensor paths of the electronic brake pedal 2 to the brake control unit of the front axle and the other sensor path to the brake control unit of the rear axle) is also possible. However, connecting the brake control units 9 and 10 to the electromechanical wheel brakes 5 and 6 of the front axle seems to be more advantageous in keeping the length of the wiring used to connect the electronic brake pedal 2 as short as possible.

[0059] In all embodiments, it is preferably proposed that the two brake control units 9, 10, specifically used to connect redundant sensor paths, are supplied by different (independent) vehicle electrical systems / on-board power grids.

[0060] According to the present invention, the braking system 1 includes two primary wheel braking modules 19 and 20, each designed to be disposed on one wheel. Each primary wheel braking module integrates one electromechanical wheel brake 5 or 6 and a corresponding assigned brake control unit 9 or 10. The two primary wheel braking modules 19 and 20 are assigned to one axle of the vehicle. At least one basic control unit 21, 22, or 23 is assigned to two additional electromechanical wheel brakes 7 or 8 on the other axle of the vehicle and is designed to receive control information and control at least one of the additional electromechanical wheel brakes 7 or 8.

[0061] A basic control unit 21 can be provided for the two electromechanical wheel brakes 7 and 8 on the same axle of the vehicle. Figure 1 , Figure 2 However, separate basic control units 22 and 23 may also be provided for each of the electromechanical wheel brakes 7 and 8 (see...). Figure 3 , Figure 4 ).

[0062] exist Figure 3 , Figure 4 In the braking system, there are two secondary wheel braking modules 24 and 25, which are designed to be arranged on one wheel respectively. Each of the two secondary wheel braking modules integrates one of the other electromechanical wheel brakes 7 and 8 and a corresponding assigned basic control unit 22 and 23.

[0063] Each basic control unit 21, 22, 23 can be supplied with control information during operation by two brake control units 9, 10 via at least one signal line 12, 26, 27. This signal line 12 can be as follows: Figure 1 , Figure 3 The diagram shows the system bus, or separate signal lines 26 and 27 could be provided from each of the brake control units 9 and 10 to the corresponding two basic control units 22 and 23, as shown. Figure 2 , Figure 4 As shown.

[0064] The primary wheel braking modules 19, 20 or their braking control units 9, 10 are connected via a signal link 12 in the form of a system bus, for example... Figure 1 , Figure 3 As shown, or they are connected via a separate signal link 28, for example, Figure 2 , Figure 4 As shown.

[0065] The corresponding speed sensor 29 of the associated wheel is connected to each brake control unit 9, 10 to provide speed data. One or more associated wheels ( Figure 1 , Figure 2 ) or two ( Figure 3 , Figure 4 The speed sensor 30 is connected to each basic control unit 21, 22, 23 to provide speed data.

[0066] At least one brake control unit 9, 10 is configured to check the control information received from the vehicle regulator 11 for the electromechanical wheel brakes 5, 6, 7, 8 before forwarding it, and to override the control information if a safety threshold is lowered. This function will be incorporated into the method framework of the present invention. Figure 5 , 6 Describe it.

[0067] Figure 5 A flowchart of the method according to the invention is shown. First, step 100 is performed: pedal sensor data indicating pedal operation of brake pedal 2 is transmitted from pedal sensors 3 and 4 to at least one of brake control units 9 and 10. Then, step 110 is performed: preprocessed data is calculated by at least one of brake control units 9 and 10. In step 120, the preprocessed data is transmitted to vehicle regulator 11 via signal links 12, 13, and 14 by at least one of brake control units 9 and 10. Step 130 includes calculating control information for at least one (particularly four) electromechanical wheel brakes 5, 6, 7, and 8 from the preprocessed data in vehicle regulator 11. In step 140, the control information for at least one (particularly all) electromechanical wheel brakes 5, 6, 7, and 8 is transmitted to at least one brake control unit 9 and 10 (that is, not directly to the electromechanical wheel brakes 5, 6, 7, and 8). Step 150 includes: determining, by means of at least one brake control unit 9, 10, whether the control information received from the vehicle regulator 11 is below a safety threshold before forwarding it to the electromechanical wheel brakes 5, 6, 7, 8; and if so, overwriting the control information in step 160 before forwarding it to the electromechanical wheel brakes 5, 6, 7, 8 in step 170. If it is determined in step 150 that the control information received from the vehicle regulator 11 is not below a safety threshold ("No" in the flowchart), then in step 180, the control information received from the vehicle regulator 11 is forwarded to the electromechanical wheel brakes 5, 6, 7, 8 without change.

[0068] Brake control units 9 and 10 can automatically calculate secondary control information based on pedal sensor data, and if the received control information is below a safety threshold, this secondary control information can be used to override the control information received from vehicle regulator 11. This has the advantage that if the control information from vehicle regulator 11 is below the safety threshold, brake control units 9 and 10 can react more quickly because the secondary control information has already been calculated in parallel with vehicle regulator 11 and is immediately available without further local calculation steps. Preferably, therefore, for example, the secondary control information is calculated in parallel by at least one brake control unit 9 or 10 with one or more of steps 110, 120, 130, or 140.

[0069] The safety threshold can be defined by a characteristic curve related to the pedal sensor data, such as... Figure 6 The example shown is for illustrative purposes only. The characteristic curves can be stored locally in at least one brake control unit 9, 10. Safety threshold a 最小 It can be determined based on the deceleration characteristic curve related to pedal sensor data, particularly the pedal force. Figure 6 The following example illustrates the deceleration characteristic curve a (solid line) related to pedal force. The deceleration request (or braking request) is represented by the pedal force in Newtons, and the desired deceleration is expressed as the standard gravitational acceleration (g = 9.80665 m / s²). 2 The unit is ) . Here, pedal force can be the directly measured pedal force or the pedal force obtained by calculating data from different sensors (force sensor and / or angle sensor and / or stroke sensor). Safety threshold a 最小 The (dashed line) represents a constant deceleration value lower than the deceleration characteristic curve. This constant deceleration value is, for example, between 0.4 and 0.8 standard gravitational accelerations, in this case, 0.6 standard gravitational accelerations. However, the safety threshold a... 最小 Always at least 0m / s 2 In other words, it is non-negative. This configuration ensures that when the deviation between the control information sent from the vehicle regulator 11 to the brake control units 9 and 10 and the deceleration characteristic curve a is relatively small, the brake control units 9 and 10 will not intervene and the control information will not be overwritten. However, at the same time, it ensures that when a deceleration request has been detected from the pedal sensor data but the vehicle regulator 11 has not implemented any deceleration in the control information (e.g., due to software or memory errors), the brake control units 9 and 10 will always intervene.

[0070] Furthermore, a safety threshold can therefore be implemented on the brake control units 9 and 10. The safety threshold intervenes when no fault is detected in the vehicle regulator. To this end, each of the brake control units 9 and 10 checks whether the target values ​​sent from the vehicle regulator 11 to the electromechanical wheel brakes 5, 6, 7, and 8 can cause a reasonable overall deceleration of the vehicle based on the braking request calculated locally on the corresponding brake control unit 9 or 10. If this is not the case, the brake control units 9 and 10 can match the braking request formed by the vehicle regulator 11, and thus improve the vehicle's safety against underbraking.

[0071] The safety threshold a should be redundantly provided on brake control units 9 and 10. 最小 It can have the following characteristics:

[0072] ● If the deceleration request sent from the outside is below the minimum value, then the safety threshold a 最小 It should be valid (that is, it should match the deceleration request sent from the outside).

[0073] ● This minimum value should be related to the force applied by the driver to the brake pedal 2.

[0074] For this purpose, direct measurement of this force is not absolutely necessary. An estimation based on sensor signals from the electronic brake pedal 2 (e.g., based on the measured pedal travel) and in the presence of knowledge of the force-travel characteristics of the electronic brake pedal 2 can replace direct force measurement.

[0075] ● The brake control units 9 and 10 store characteristic curves a(F) of the deceleration request related to the measured or estimated force. 踏板 ()( Figure 6 (The solid line in the middle).

[0076] ○ This characteristic curve has a very flat profile in the low-force region, thus indicating good braking performance.

[0077] ○ With an ergonomically favorable force (significantly lower than the 500N force allowed by the design for the backup stage according to ECE R13H), the deceleration request is designed to be about 1g, resulting in full braking on normal ground (dry road).

[0078] ○ As the pedal force increases further, the deceleration request increases to 2…3g. Although this deceleration cannot be physically implemented, its effect is that the braking force can be increased to a certain extent, so that almost complete braking can still be implemented even if the wheel brakes 5, 6, 7, 8 are in poor condition (e.g., due to corrosion or heat fade).

[0079] ●Safety threshold a 最小 (F踏板 ()( Figure 6 The highlight of the dashed line in the figure is the following fact: the minimum value (i.e., the safety threshold a) 最小 The activation threshold is located at a constant distance below the aforementioned characteristic curve of the deceleration request. If this distance is referred to as a... tol Then the following formula holds:

[0080] a 最小 (F 踏板 )=MAX(0,a(F 踏板 )–a tol ).

[0081] ● In this case, parameter a can be selected. tol , making

[0082] ○ Achieve braking performance sufficient for most traffic conditions while maintaining an ergonomically acceptable pedal force (which results in full braking under normal system function). For example, the parameter design objective could be to meet the service braking performance specified in ECE R13H (6.43 m / s). 2 ).

[0083] ○ There is robustness against misactivation of security thresholds.

[0084] In this case, it can be considered

[0085] ■ The characteristic curve stored in the vehicle regulator 11 within the scope of vehicle application may deviate from the characteristic curve used to determine the safety threshold by a specific amount.

[0086] ■ The vehicle regulator 11 enables the deceleration desired by the driver to be achieved to some extent by the power system (e.g., during regenerative braking).

[0087] ■ To further enhance robustness against misactivation of the safety threshold in the event of a short-term deviation between an externally sent driver braking request and the characteristic curve stored in the brake control unit, it is advantageous to additionally include the safety threshold a 最小 Its activation is tied to time-related conditions.

[0088] ●If the safety threshold is enabled, that is, if the driver braking request sent from the outside is below the limit a 最小 (F 踏板 If the brake control unit instead executes the locally calculated driver braking request a(F), then the brake control unit will execute the locally calculated driver braking request a(F). 踏板 ).

[0089] ● It should be determined based on the specific application.

[0090] ○ Once this exceeds the safety threshold value again

[0091] ○ At the start of the next braking process

[0092] ○ At the start of the next driving cycle

[0093] Should we switch back to the driver braking request sent from an external source?

[0094] ●In summary, the advantage is that when a safety threshold is enabled, the corresponding information is stored in the non-volatile memory of the control unit to support later fault analysis.

[0095] List of reference numerals in the attached diagram:

[0096] 1. Braking system

[0097] 2. Brake pedal

[0098] 3. Pedal Sensor

[0099] 4. Pedal Sensors

[0100] 5. Electromechanical wheel brakes

[0101] 6. Electromechanical wheel brakes

[0102] 7 Electromechanical wheel brakes

[0103] 8. Electromechanical wheel brakes

[0104] 9. Brake control unit

[0105] 10. Brake Control Unit

[0106] 11 Vehicle regulator

[0107] 11A Vehicle Chassis Functions

[0108] 12 Signal Links / Signal Lines

[0109] 13 Signal Links / Signal Lines

[0110] 14. Signal Link / Signal Line

[0111] 15. Braking request signal line

[0112] 16 Braking Request Signal Line

[0113] 17 Braking Circuit

[0114] 18 Braking Circuit

[0115] 19. Primary wheel braking module

[0116] 20 Primary wheel braking module

[0117] 21 Basic Control Unit

[0118] 22 Basic Control Unit

[0119] 23 Basic Control Unit

[0120] 24 Secondary wheel braking modules

[0121] 25 Secondary wheel braking modules

[0122] 26. Signal Link / Signal Line

[0123] 27. Signal Link / Signal Line

[0124] 28. Signal Link / Signal Line

[0125] 29. Speed ​​sensor

[0126] 30 Speed ​​sensor

[0127] 100 steps

[0128] 110 steps

[0129] 120 steps

[0130] 130 steps

[0131] 140 steps

[0132] 150 steps

[0133] 160 steps

[0134] 170 steps

[0135] 180 steps

Claims

1. A method for controlling a braking system (1), the method comprising the steps of: - Pedal sensor data indicating pedal operation of the electronic brake pedal (2) is transmitted (100) from at least one pedal sensor (3, 4) of the brake pedal (2) to at least one brake control unit (9, 10). - Preprocessed data is calculated (110) by the at least one brake control unit (9, 10). - The preprocessed data (120) is transmitted by the at least one brake control unit (9, 10) to the vehicle regulator (11) of the motor vehicle via signal links (12, 13, 14). - Control information for at least one electromechanical wheel brake (5, 6, 7, 8) is calculated (130) in the vehicle regulator (11) based on preprocessed data. - Control information for the at least one electromechanical wheel brake (5, 6, 7, 8) is transmitted (140) to at least one brake control unit (9, 10). Before forwarding control information to the at least one electromechanical wheel brake (5, 6, 7, 8), the at least one brake control unit (9, 10) determines (150) whether the control information received from the vehicle regulator (11) is below a safety threshold (a 最小 If the control information is below a safety threshold, the control information is overridden (160) before being forwarded (170) to the at least one electromechanical wheel brake (5, 6, 7, 8).

2. The method as described in claim 1, characterized in that, Security threshold (a) 最小 The characteristic curve (a) associated with the pedal sensor data is defined by the characteristic curve (a) which is locally stored in the at least one brake control unit (9, 10).

3. The method as described in claim 1 or 2, characterized in that, The at least one brake control unit (9, 10) automatically calculates secondary control information from pedal sensor data, within a safety threshold (a 最小 If the value is lower than the value, the secondary control information is used to override the control information received from the vehicle regulator (11).

4. The method according to any one of claims 1 to 3, characterized in that, At least one method step is executed in parallel in two braking control units (9, 10).

5. The method according to any one of claims 1 to 4, characterized in that, Security threshold (a) 最小 The safety threshold (a) is determined based on the deceleration characteristic curve (a) related to pedal sensor data, particularly pedal force. 最小 The deceleration value is lower than the deceleration characteristic curve by a constant deceleration value, which is, for example, between 0.4 and 0.8 standard gravitational accelerations; however, a safety threshold (a) is required. 最小 Preferably, it is always at least 0 m / s 2 .

6. The method according to any one of claims 1 to 5, characterized in that, At the safety threshold (a) 最小 If the control information is lower than the specified value, the overriding of the control information will continue until... - New control information from the vehicle regulator (11) is again above the safety threshold (a 最小 ),or - This indicates the end of the current braking process or the start of a new braking process, or - This determines the end of the vehicle's current driving cycle or the start of a new driving cycle.

7. The method according to any one of claims 1 to 6, characterized in that, Only when the control information received from the vehicle regulator (11) remains below the safety threshold (a 最小 The control information is overridden (160) only when a predetermined minimum duration is reached, for example, from 25 milliseconds to 250 milliseconds, before being forwarded (170) to the at least one electromechanical wheel brake (5, 6, 7, 8).

8. A braking system (1), particularly a braking system for a motor vehicle, the braking system comprising: A brake pedal (2) having at least one pedal sensor (3, 4) for obtaining a driver's braking request by means of pedal sensor data. At least one electromechanical wheel brake (5, 6, 7, 8), preferably four electromechanical wheel brakes (5, 6, 7, 8). At least one brake control unit (9, 10), preferably two brake control units (9, 10), and Vehicle regulator (11) of a motor vehicle The brake control unit (9, 10) is configured to calculate preprocessed data from pedal sensor data and provide the preprocessed data to the vehicle regulator (11) via signal links (12, 13, 14). The vehicle regulator (11) is configured to calculate control information for at least one electromechanical wheel brake (5, 6, 7, 8) based on preprocessed data, and transmit the control information to the at least one wheel brake (5, 6, 7, 8) via at least one signal link (12, 13, 14, 26, 27). Its features are, At least one braking control unit is configured to perform the method as described in any one of the preceding claims.

9. The braking system as claimed in claim 8, characterized in that, The braking system (1) includes at least two braking control units (9, 10), each of which is configured to perform the method as described in any one of the preceding claims.

10. The braking system as claimed in claim 8 or 9, characterized in that, The braking system includes two primary wheel braking modules (19, 20), each designed to be located on one of the vehicle wheels. Each of the two primary wheel braking modules integrates an electromechanical wheel brake (5, 6) and a corresponding associated brake control unit (9, 10).

11. The braking system as claimed in any one of claims 9 and 10, characterized in that, The pedal sensors (3, 4) are each connected to the two brake control units (9, 10) via a separate brake request signal line (15, 16).

12. The braking system (1) as claimed in any one of claims 8 to 11, characterized in that, The brake pedal (2) includes at least two pedal sensors (3, 4) that determine two different measurement variables, particularly force sensors and / or displacement sensors and / or angle sensors, and signals from at least the two pedal sensors (3, 4) that determine the different measurement variables are able to be transmitted to each brake control unit (9, 10) during operation.

13. The braking system (1) as claimed in any one of claims 9 to 12, characterized in that, The brake pedal (2) includes at least two redundant pedal sensors (3, 4) that determine the same measurement variables, in particular two force sensors and / or two stroke sensors and / or two angle sensors, and signals from each redundant pedal sensor (3, 4) can be transmitted to a corresponding brake control unit (9, 10) during operation.

14. The braking system (1) as claimed in any one of claims 10 to 13, characterized in that, Two primary wheel brake modules (19, 20) are assigned to one axle of the vehicle, and at least one basic control unit (21, 22, 23) is assigned to two additional electromechanical wheel brakes (7, 8) on the other axle of the vehicle. The at least one basic control unit is designed to receive control information and control at least one of the two additional electromechanical wheel brakes (7, 8).

15. The braking system (1) as claimed in claim 14, characterized in that, The at least one basic control unit (21, 22, 23) is capable of receiving control information during operation from two brake control units (9, 10) via separate signal lines (26, 27).

16. The braking system (1) as claimed in claim 14 or 15, characterized in that, The braking system (1) includes two secondary wheel braking modules (24, 25), each designed to be mounted on a wheel. Each of the two secondary wheel braking modules integrates one of the two additional electromechanical wheel brakes (7, 8) and a corresponding assigned basic control unit (22, 23). Each of the basic control units (22, 23) is designed to receive control information and control the assigned electromechanical wheel brake (7, 8).

17. The braking system (1) as claimed in any one of claims 14 to 16, characterized in that, The two basic control units (22, 23) are able to receive control information during operation via separate signal lines (26, 27) from the two braking control units (9, 10).

18. The braking system (1) as claimed in any one of claims 8 to 17, characterized in that, The vehicle regulator (11) is configured to transmit control information for at least one electromechanical wheel brake (5, 6, 7, 8) to two brake control units (9, 10) via signal lines (12, 13, 14), preferably via two separate signal lines (13, 14). The brake control units (9, 10) are configured to forward the control information to at least one electromechanical wheel brake (5, 6, 7, 8), particularly to four electromechanical wheel brakes (5, 6, 7, 8).

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