Brake control device for a vehicle and method for operating a brake control device for a vehicle

Abstract

The invention provides a brake control device (10) for a vehicle (F), comprising a control device (SE) which is connected to a brake force amplifier device (BV) and to an electric machine (EM) of the vehicle, wherein the control device (SE) is designed to recognize an operational failure or an operational fault of the brake force amplifier device (BV), to recognize a minimum value (minM1) of a first brake torque (M1) of the electric machine (EM) as a regenerative brake torque, wherein the minimum value (minM1) of the first brake torque (M1) corresponds to a brake torque having the smallest absolute value at all vehicle speeds which can be generated by the electric machine (EM), and to operate the electric machine (EM) in order to generate at least the minimum value (minM1) of the first brake torque (M1) by the electric machine (EM) upon recognition of an operational failure or an operational fault of the brake force amplifier device (BV) and for a brake request.

Description

Technical Field

[0001] This invention relates to a braking control device for a vehicle and a method for operating the braking control device for a vehicle. Background Technology

[0002] In electrically powered vehicles, a common drive concept utilizes the braking effect of an electric motor. For this purpose, brake force generators or brake force amplifiers are known, which can be electronically controlled when braking is required.

[0003] As is well known, hydraulic braking systems can be used in vehicles, with different braking systems specifically designed for amplifying braking force. In the event of a braking system failure, the braking force amplification can be eliminated, and the driver can generate hydraulic pressure through the brake pedal at the mechanical retraction level. This hydraulic pressure can then be converted into vehicle deceleration through the wheel brakes.

[0004] Electric vehicles accelerate using electric motors and can recover energy during braking using these motors (regenerative braking). To recover energy, the electric motor generates a resistance torque (corresponding to its power hyperbola), which causes the vehicle to decelerate accordingly. This regeneration is typically controlled by the braking system to ensure or at least increase driving stability, as the braking torque of the electric motor is highly dependent on rotational speed or vehicle speed. However, since drivers often desire a constant deceleration (a mixture of hydraulic and electric braking torque), control over the generation of braking torque may be necessary. Therefore, in the event of a braking system failure, regeneration is usually also largely deactivated.

[0005] A drive system for an all-wheel-drive vehicle is described in WO 2013 / 083243 A1. Summary of the Invention

[0006] The present invention provides a braking control device for a vehicle and a method for operating the braking control device for a vehicle.

[0007] The preferred modification is the subject of this instruction manual.

[0008] Advantages of this invention:

[0009] The present invention is based on the idea of ​​providing a braking control device for a vehicle and a method for operating the braking control device for a vehicle, wherein, in the event of a malfunction or failure of the brake force amplifier device, the vehicle's deceleration performance can be improved by generating regenerative braking torque.

[0010] Advantageously, it can support deceleration at the mechanical retraction level to improve deceleration in the event of a failure in the braking force amplification, and thus enable a higher vehicle deceleration than without regenerative braking torque when the pedal force is the same, by utilizing additional regenerative braking torque.

[0011] In this situation, it is advantageous to consider the current performance of the motor as a generator in relation to its operating performance. Here, the proportion of deceleration contributed by the generator (the proportion of braking torque) can be taken into account.

[0012] According to the present invention, a braking control device for a vehicle is capable of controlling the braking behavior of the vehicle. The braking control device includes: a control device connected to or capable of being connected to a brake force amplifier device and a motor of the vehicle; wherein the control device is configured to identify malfunction or failure of the brake force amplifier device; identify and / or know the minimum value of a first braking torque of the motor as a regenerative braking torque, wherein the minimum value of the first braking torque corresponds to the braking torque with the minimum absolute value at all vehicle speeds that can be generated by the motor; and, in the event of identification of malfunction or failure of the brake force amplifier device and in response to braking requirements, manipulate the motor such that the motor generates at least the minimum value of the first braking torque.

[0013] Operational failure can be a complete or partial malfunction of the brake amplifier unit. Operational failure can be any fault that can limit brake amplification or other types of functional failure.

[0014] Regenerative braking torque can decrease as vehicle speed increases, with the minimum value at all speeds being identifiable or predetermined, for example, according to road traffic regulations or manufacturer-preset permissible speed ranges. Braking requirements can be met by the driver or via a controller (autonomous).

[0015] Braking behavior can be, for example, a vehicle braking process that utilizes frictional braking torque and / or regenerative braking torque and / or any other type of braking force on the vehicle in order to slow the rotation of the wheels.

[0016] Here, deceleration can be achieved according to the vehicle's preset settings, which the user can select arbitrarily low or high (strong).

[0017] Here, it is possible to determine the operating state of the motor as a generator, which corresponds to the degree to which the motor can instantaneously or overall generate regenerative braking torque at all speeds applicable to it. Therefore, as vehicle speed increases, the first braking torque that can be generated can be lower than the first braking torque at lower speeds. It is possible to determine the minimum value of the first braking torque, which is at least applicable at all vehicle speeds and when the motor is operating as a generator.

[0018] Based on the understanding of the performance of the motor as a generator and thus as a device for generating regenerative braking torque, the first braking torque can be adaptively and dynamically increased and / or decreased over time, for example, to achieve a preset first braking torque, for example, to reach at least a minimum value, or to be realized as a sum of the second braking torque with other braking devices.

[0019] In other words, it is possible to estimate the preset share of the total braking torque of the vehicle that can be provided by the generator at all times or under the current (to be estimated) conditions, and then to what share the additional (second) braking torque can be reduced, since the minimum value can always be applied when there is no fault on the motor or other components of the drive unit or braking system.

[0020] The vehicle can be a car with a drive unit, which may include an electric motor.

[0021] Therefore, in the event of a malfunction or operational failure of the brake force amplifier and / or in the mechanical retraction phase, the vehicle's motor (electric motor) can be considered as an independent, separate braking circuit, and its potential braking action can be utilized in addition to hydraulic braking. Since the electric motor achieves the lowest torque at high speeds according to its performance hyperbola, the available braking torque can be preset in this way (or, the higher the power of the electric motor, the higher the braking torque at high speeds or vehicle speeds). It is also feasible to always require only the minimum deceleration achievable even at high speeds for the electric motor. This torque, advantageously available when the motor and brake control components are functioning correctly, can be considered for the design of braking action in the retraction phase. However, it is also feasible to require a larger regenerative (first) braking torque at lower speeds to further reduce the pedal force required for vehicle braking, and thus reduce the difference in braking action between normal conditions (with brake force amplification) and fault conditions. For example, the achievable deceleration in the mechanical retraction phase can be 2.44 m / s² with a pedal force of 500 N. 2 For example, it could come only from the second braking torque, or only from the minimum value, or from the sum of both.

[0022] According to a preferred embodiment of the braking control device, the braking control device includes a pedal sensor device and / or a control device connected to the pedal sensor device and configured to detect the operation of the brake pedal and / or accelerator pedal in the vehicle, wherein the control device is configured to infer the driver's braking requirement from the operation of the brake pedal and / or accelerator pedal.

[0023] This operation can be performed by the driver.

[0024] According to a preferred embodiment of the braking control device, the pedal sensor device is configured to identify the pressure and / or force and / or position of the brake pedal and / or accelerator pedal, and the control device is configured to infer the degree of braking requirement from the pressure and / or force and / or position of the brake pedal and / or accelerator pedal and cause it to generate at least partially as a first braking torque on the motor.

[0025] This degree corresponds to the adjustment angle or deflection of the pedal from its rest position and reflects the intensity of the required braking action. Then, depending on the degree and intensity of the braking action, the required braking torque can either be generated solely by the motor if the minimum value is already sufficient or if the motor operates at a lower speed than the speed used to generate the minimum value and thus can generate a first braking torque greater than the minimum value, or it can be generated together with a second braking torque, for example, from a hydraulic braking system or another braking system.

[0026] According to a preferred embodiment of the braking control device, the control device further includes provisions for recognizing the release of the accelerator pedal and requesting a constant first braking torque greater than or equal to a minimum value from the motor; and / or recognizing the operation of the brake pedal via a pedal sensor device and generating a first braking torque according to the degree of braking requirement; and / or recognizing the operation of the brake pedal via another sensor device and requesting a constant first braking torque greater than or equal to a minimum value; and / or recognizing the operation of the brake pedal via another sensor device and requesting a first braking torque according to a preset characteristic curve.

[0027] The braking torque that can be generated based on this level can be converted and transformed using a proportional factor relative to the actual force generated by the driver on the brake pedal, for example, proportionally, wherein the proportional factor can be related to the motor and the minimum achievable value, can be adaptively changed, or can be preset.

[0028] According to a preferred embodiment of the braking control device, the control device is connected to a hydraulic braking device and / or another braking device, and is configured to generate a second braking torque on the hydraulic braking device and / or the other braking device when braking is required. This second braking torque, together with the minimum value of the first braking torque, generates a preset total vehicle braking torque.

[0029] Here, in order to generate a total braking torque that is at least minimally contributed by the motor, but if the current operating state of the motor allows, it can also contribute a first braking torque greater than the minimum value to better support the mechanical retraction aspect. Thus, it is possible to either increase the total braking torque or decrease the proportion of the second braking torque.

[0030] According to a preferred embodiment of the braking control device, the control device is connected to the vehicle's battery and is configured to know or determine the battery's charging state and / or know or determine the acceptable overload operation of the motor, and for a preset time and by the acceptable overload operation of the motor, require a first braking torque greater than a minimum value, and / or require a first braking torque greater than a minimum value and reach an acceptable overcharge state of the battery.

[0031] Under such requirements of the braking system and / or braking control device, the motor can operate under temporary overload conditions to at least temporarily increase the currently possible total braking torque or the first braking torque. It is also feasible for the electric drive unit to temporarily achieve a slightly increased battery state of charge. Typically, the maximum state of charge is chosen to ensure optimal battery life. In rare failure scenarios, this can be discarded for a short time, especially in an acceptable overcharge state known to the battery and which will not cause damage to the battery in a short period, or at least is tolerable, similarly for overload operation. Maximum possible deceleration can be achieved by reporting the maximum possible regenerative braking torque to the braking system.

[0032] Braking devices can include friction brakes or any other type of non-regenerative brake.

[0033] Furthermore, in addition to signals used to determine the driver's braking expectations, other parameters containing information about the dynamic driving state and on which the required braking torque can be adjusted can be advantageously used. Especially when braking torque is required on the rear axle, this allows for maximum braking while maintaining vehicle stability, or at least for improving vehicle stability. These signals can be, for example, wheel speed signals and / or steering angle and / or yaw rate and / or lateral acceleration. Therefore, the first and / or second braking torques can be used and adjusted selectively. Additionally, hydraulic pressure formation on each wheel can be reduced (braking force distribution or ABS function), especially to compensate for potential limitations in the adjustment accuracy of other regulators used to generate braking torque (e.g., automatic parking brake APB). This consideration of driving dynamics can be achieved provided that the appropriate and necessary signals are available and the braking control device is still able to process these signals to pre-set the regenerative braking torque in a correspondingly adaptive manner. If the braking control unit is no longer able to process these signals accordingly, the generator control unit can generate a constant, low regenerative torque, similar to a drag torque, once the accelerator pedal is released. This constant, low regenerative braking torque can be selected to keep the vehicle stable in all driving conditions, taking into account the driven axle accordingly.

[0034] According to the present invention, in a method for operating a braking control device for a vehicle to control the braking behavior of the vehicle: identifying braking requirements and / or the necessity of braking behavior using the braking control device according to the invention; identifying malfunction or failure of the brake force amplifier device; determining the minimum value of the first braking torque of the motor as the regenerative braking torque, wherein the minimum value of the first braking torque corresponds to those braking torques with the smallest absolute value at all vehicle speeds that can be generated by the motor; and generating at least the minimum value of the first braking torque by the motor in the event of malfunction or failure of the brake force amplifier device and when braking and / or braking behavior are required.

[0035] There is a necessity to control and execute braking behavior using braking control devices and / or braking equipment.

[0036] According to a preferred embodiment of the method, when braking is requested by pedal operation of the brake pedal and / or accelerator pedal, the pressure and / or force and / or position of the brake pedal and / or accelerator pedal are identified using a pedal sensor device and / or other sensing devices, and the degree of braking request is inferred from the pressure and / or force and / or position of the brake pedal and / or accelerator pedal, and a constant or related first braking torque is generated.

[0037] Other sensing devices can be common sensors for vehicles, acceleration, force, pedal movement or pressure, navigation systems, or any other type of sensing device. Additional sensing devices can be provided and operated as independent sensing devices, such as pedal sensors or other components and / or brake control devices independent of the vehicle.

[0038] According to a preferred embodiment of the method, the release of the accelerator pedal is detected and a constant first braking torque greater than or equal to a minimum value is requested from the motor; and / or the operation of the brake pedal is detected by a pedal sensor device and a first braking torque is generated according to the degree of braking request; and / or the operation of the brake pedal is detected by another sensing device and a constant first braking torque greater than or equal to a minimum value is requested; and / or the operation of the brake pedal is detected by another sensing device and a first braking torque is requested according to a preset characteristic curve.

[0039] The characteristic curve can be, for example, the first braking torque or the nonlinear characteristic curve of the motor with respect to its generator performance.

[0040] Therefore, in the event of a brake system failure and / or a malfunction or failure of the brake force amplifier, the motor can be installed into the vehicle's braking mechanism according to different feasible solutions.

[0041] Once the driver fully releases the accelerator pedal, the electric motor operates to generate a constant initial braking torque independent of the brake pedal's operation. This braking torque then acts similarly to the (increased) drag torque of an internal combustion engine.

[0042] Furthermore, once the driver operates the brake pedal, the driver's braking intention can be identified via a pedal travel sensor (PTS), which is available in the braking system and can be included in or connected to the brake control unit. The control unit can then request a corresponding first braking torque from the motor via an interface. This braking torque can vary from the driver's braking intention (sensed via the PTS) up to the maximum first braking torque to be used or available. This is contingent on the PTS sensor and the ECU (control unit) still functioning, at least in this respect.

[0043] Furthermore, once the driver actuates the brake pedal, the driver's braking intention can be identified via a pressure sensor (DS), which is available in the braking system and can be included in or connected to the brake control unit. The control unit can then request a corresponding first braking torque from the motor via an interface. This first braking torque can vary from the driver's braking intention (sensed by the DS) up to the maximum first braking torque to be used or available. This is contingent on the PTS sensor and the ECU (control unit) still functioning at least in this respect.

[0044] The characteristics of the braking system can also be applied when combined with the braking control device, and vice versa.

[0045] Sensing of brake pedal operation can also be achieved through a separate sensor on the brake pedal (an additional sensor) (e.g., BLS). If brake pedal operation is detected, the motor can generate a constant braking torque.

[0046] Sensing the driver's braking expectation can be achieved through a separate sensing device on the brake pedal (such as a pedal travel sensor). The motor can then generate a braking torque that is proportional to or preset via a non-linear characteristic curve based on the driver's braking expectation (brake pedal travel).

[0047] Therefore, the motor can generate a constant braking torque that is proportional to the position of the brake pedal and / or defined by a non-linear characteristic curve. This first braking torque can then be superimposed on the hydraulic braking torque generated when the driver operates the brake pedal, and thus the vehicle can achieve a greater deceleration than can be achieved using hydraulic braking torque alone.

[0048] In addition to the regenerative braking torque, a second braking torque can advantageously be requested via one or more additional regulators. This could be, for example, the electric parking brake or the drag torque of an internal combustion engine. Here, the control unit can coordinate and request these braking torques to achieve optimal and measurable braking effect for the driver. This is achievable for the vehicle's braking system and braking control unit, provided that the desired deceleration can be determined from the signals of the aforementioned sensors and / or motors.

[0049] Furthermore, the electric drive unit and / or other regulators used can inform / identify the current possible first and / or second braking torques through an interface, and thus can utilize the possible braking action in an optimal manner.

[0050] According to a preferred embodiment of the method, when braking is required, a second braking torque is generated on the hydraulic braking device and / or an additional braking device, which together with the minimum value of the first braking torque generates a preset total vehicle braking torque.

[0051] It is able to identify the currently available second braking torque and / or assess the second braking torque available in the foreseeable future and identify the total braking torque that can be generated.

[0052] According to a preferred embodiment of the method, the operating state of the motor and the first braking torque that can be generated on the motor are continuously or at preset time intervals.

[0053] The braking control device can also be characterized by the features and advantages mentioned in combination with the method, and vice versa.

[0054] Other features and advantages of embodiments of the present invention will become apparent from the following description with reference to the accompanying drawings. Attached Figure Description

[0055] The present invention will now be described in detail with reference to the embodiments shown in the schematic diagrams in the accompanying drawings.

[0056] in:

[0057] Figure 1 A schematic diagram of a braking control device according to an embodiment of the present invention is shown;

[0058] Figure 2 shows a diagram of the braking torque on the motor;

[0059] Figure 3 A block diagram of method steps for operating a braking control device for a vehicle according to an embodiment of the present invention is shown.

[0060] In the accompanying drawings, the same reference numerals denote the same or functionally identical elements. Detailed Implementation

[0061] Figure 1 A schematic diagram of a braking control device according to an embodiment of the present invention is shown.

[0062] For a braking control device 10 of vehicle F, the braking behavior of the vehicle can be controlled by the braking control device, which includes a control device SE connected to or capable of being connected to the vehicle's brake force amplifier device BV and motor EM; wherein the control device SE is configured to identify malfunction or failure of the brake force amplifier device BV; identify and / or know the minimum value minM1 of the first braking torque M1 of the motor EM as the regenerative braking torque, wherein the minimum value minM1 of the first braking torque M1 corresponds to the braking torque with the smallest absolute value at all vehicle speeds that can be generated by the motor EM; and when the malfunction or failure of the brake force amplifier device BV is identified and in accordance with a braking requirement, the motor EM is manipulated such that the motor EM generates at least the minimum value minM1 of the first braking torque M1. The brake control device 10 may include a pedal sensor device PS and / or a control device SE may be connected to the pedal sensor device PS and configured to detect the operation of the brake pedal and / or accelerator pedal in the vehicle, wherein the control device SE is configured to infer the driver's braking requirement from the operation of the brake pedal and / or accelerator pedal.

[0063] Furthermore, a second braking torque M2 can be generated on the hydraulic braking device HB in the vehicle and / or on another braking device WB, and the braking control device 10 and its control device SE can be connected thereto, which can generate a preset total braking torque on the vehicle when braking is required. This second braking torque can be combined with the minimum value minM1 of the first braking torque to generate a preset total braking torque on the vehicle.

[0064] Figure 2 shows a diagram of the braking torque on the motor.

[0065] Figure 2a The diagram illustrates the correlation between the first braking torque M1 and the vehicle speed, which the motor itself can generate. At this speed, the motor also rotates as the vehicle moves, and this speed is converted into an angular velocity ω. Here, the maximum speed ω can be limited. max At this speed, the minimum value of the first braking torque, minM1, can be generated.

[0066] Then, at lower speeds, a higher first braking torque can be advantageously generated based on the power hyperbola, where the maximum torque M1 can also be limited. max For example, for system design on vehicles (motor and / or battery charging). For overload operation, the hyperbola can move to P0.

[0067] according to Figure 2b The signals from the accelerator pedal GP and brake pedal BP (from their respective sensors) within the time range t are shown. The accelerator pedal GP can be released between t1 and tn. During this time, a constant first braking torque M1 can be generated on the motor. If the brake pedal BP is operated between t2 and t3 at this time, a braking torque M1 can be generated according to the time range t1. Figure 2b The bottom diagram also shows the ability to add a constant additional torque to the first braking torque, for example, to the minimum value minM1. However, on the other hand, it is also possible to generate an additional torque to the first braking torque that adapts to changes in the degree of deflection or pressure on the brake pedal BP (third diagram). This additional torque can begin at time t2 or slightly later at time t4 and end at time t3.

[0068] Figure 3 A block diagram of method steps for operating a braking control device for a vehicle according to an embodiment of the present invention is shown.

[0069] In a method for operating a braking control device for a vehicle to control the braking behavior of the vehicle, S1 braking requirement and / or necessity is identified in order to perform braking behavior using the braking control device according to the invention; S2 malfunction or failure of the braking force amplifier device is identified; S3 the minimum value of the first braking torque of the motor is determined as the regenerative braking torque, wherein the minimum value of the first braking torque corresponds to the braking torque with the smallest absolute value at all vehicle speeds that can be generated by the motor; and in the event of malfunction or failure of the braking force amplifier device and in the event of braking requirement and / or need for braking behavior, at least the minimum value of the first braking torque is generated by the motor.

[0070] Although the invention has been fully described above with reference to preferred embodiments, the invention is not limited thereto and can be modified in various ways.

Claims

1. A braking control device (10) for a vehicle (F), said braking control device being capable of controlling the braking behavior of the vehicle, said braking control device comprising: - A control device (SE) connected to or capable of connecting to the vehicle's brake force amplifier (BV) and to the electric motor (EM); wherein the control device (SE) is configured to: - Identify malfunctions or failures in the brake force amplifier (BV) device; - Identify and / or obtain the minimum value (minM1) of the first braking torque (M1) of the motor (EM) as the regenerative braking torque, wherein the minimum value (minM1) of the first braking torque (M1) corresponds to the braking torque with the minimum absolute value at all vehicle speeds that the motor (EM) can generate; and - In the event of a malfunction or failure of the brake amplifier device (BV) and in response to braking requirements, the motor (EM) is operated such that the motor (EM) generates at least a minimum value (minM1) of a first braking torque (M1).

2. The braking control device (10) according to claim 1, the braking control device includes a pedal sensor device (PS), and / or wherein the control device (SE) is connected to the pedal sensor device (PS), and the control device is configured to detect the operation of the brake pedal and / or accelerator pedal in the vehicle, wherein the control device (SE) is configured to infer the driver's braking requirement from the operation of the brake pedal and / or accelerator pedal.

3. The braking control device (10) according to claim 2, wherein the pedal sensor device (PS) is configured to identify the pressure and / or force and / or position of the brake pedal and / or accelerator pedal, and the control device (SE) is configured to infer the degree of braking requirement from the pressure and / or force and / or position of the brake pedal and / or accelerator pedal, and generate the degree of braking requirement at least in part on the motor as a first braking torque (M1).

4. The braking control device (10) according to claim 2 or 3, wherein, The control device (SE) is also provided for: - Recognizes the release of the accelerator pedal and requests a constant first braking torque greater than or equal to the minimum value from the motor (EM); and / or - The pedal sensor device (PS) identifies the operation of the brake pedal and generates a first braking torque according to the degree of braking requirement; And / or - The operation of the brake pedal is identified by an additional sensing device, and a constant first braking torque greater than or equal to the minimum value is required; And / or - The operation of the brake pedal is identified by an additional sensor and the first braking torque is required according to a preset characteristic curve.

5. The braking control device (10) according to any one of claims 1 to 3, wherein, The control device (SE) is connected to the hydraulic braking device and / or to another braking device and is configured to generate a second braking torque (M2) on the hydraulic braking device (HB) and / or the other braking device (WB) when braking is required. The second braking torque, together with the minimum value (minM1) of the first braking torque, generates a preset total braking torque for the vehicle.

6. The braking control device (10) according to any one of claims 1 to 3, wherein, The control device (SE) is connected to the vehicle's battery and is configured to know or determine the battery's state of charge, and / or know or determine the acceptable overload operation of the motor (EM), and for a preset time, require a first braking torque (M1) greater than a minimum value due to the acceptable overload operation of the motor (EM), and / or require a first braking torque greater than a minimum value and reach an acceptable overcharge state of the battery.

7. A method for operating a braking control device (10) for a vehicle (F) to control the braking behavior of the vehicle, the method comprising the steps of: - Identify braking requirements and / or necessities in order to perform braking actions using the braking control device (10) according to any one of claims 1 to 6; - Identify malfunctions or failures in the brake force amplifier (BV) unit; - Determine the minimum value (minM1) of the first braking torque (M1) of the motor (EM) as the regenerative braking torque, wherein the minimum value (minM1) of the first braking torque (M1) corresponds to the braking torque with the minimum absolute value at all vehicle speeds that can be generated by the motor (EM); and - In the event that the brake amplifier device (BV) malfunctions or fails and braking and / or braking behavior is required, the motor (EM) generates (S4) at least a minimum value (minM1) of the first braking torque (M1).

8. The method according to claim 7, wherein, When braking is requested by pedal operation of the brake pedal and / or accelerator pedal, the pressure and / or force and / or position of the brake pedal and / or accelerator pedal are identified by a pedal sensor device (PS) and / or by other sensing devices, and the degree of braking request is inferred from the pressure and / or force and / or position of the brake pedal and / or accelerator pedal, and a constant or degree-related first braking torque is generated.

9. The method according to claim 8, wherein, The release of the accelerator pedal is detected, and a constant first braking torque greater than or equal to the minimum value is requested from the motor (EM); and / or - The brake pedal operation is identified by the pedal sensor device (PS), and a first braking torque is generated according to the degree of braking requirement; And / or - The operation of the brake pedal is identified by an additional sensing device, and a constant first braking torque greater than or equal to the minimum value is required; And / or - The operation of the brake pedal is identified by an additional sensor, and the first braking torque is required according to a preset characteristic curve.

10. The method according to any one of claims 7 to 9, wherein, When braking is required, a second braking torque (M2) is generated on the hydraulic braking device (HB) and / or an additional braking device (WB), which together with the minimum value of the first braking torque (minM1) generates the vehicle's preset total braking torque.

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