Braking arrangement for a motor vehicle and method for controlling the same

Abstract

The invention relates to a brake system (34) of a motor vehicle (2) and a method for controlling the brake system, the brake system having a service brake system (38) with friction brakes (40a, 40b, 42a, 42b) that can be actuated by a pressure medium, a continuous brake system (44) configured as a hydraulic or electric retarder, at least one electric machine (24) that is in a driving connection with a wheel (6a, 6b) on an axle (4) and can at least be operated as a generator, and a foot brake valve (48) that can be actuated by means of a brake pedal (46), wherein the foot brake valve (48) has a brake value transmitter (50) and a brake pedal actuator (52) for generating a return force acting on the brake pedal (46), and wherein the mentioned components of the brake system (23) can be controlled by means of an electronic controller (36), wherein a brake force request signaled by means of a deflection of the brake pedal (46) is satisfied in the order of the electric machine (24) in generator operation, the retarder (44) and the service brake system (38) with priority, and wherein the allocation of the brake force to the components of the brake system (23) is signaled to the driver of the motor vehicle (2) in an appropriate manner. In order to signal information to the driver about the allocation of the brake force without the driver having to remove his gaze from the traffic space in front of him for this purpose, it is provided that, when a change in the allocation of the brake force to the components (24, 38, 44) of the brake system (23) occurs at least once, a signal force (S1, S2, S3, S4) that can be perceived haptically is briefly superimposed on the return force acting on the brake pedal (46) by means of the brake pedal actuator (52).

Description

Technical Field

[0001] This invention relates to a braking system for a motor vehicle and a method for controlling the braking system. The braking system includes a service braking system with a friction brake operable by a pressure medium, a continuous braking system configured as a hydraulic or electric reducer, at least one motor that is in transmission connection with a wheel on an axle and can operate as a generator, and a foot brake valve operable by means of a brake pedal. The foot brake valve has a brake value transmitter and a brake pedal actuator for generating a reset force acting on the brake pedal. All the components of the braking system are controllable by means of an electronic controller. Braking force requests signaled by deflection of the brake pedal are satisfied in priority in the order of the motor, reducer, and service braking system operating as a generator. The distribution of braking force to the components of the braking system is communicated to the driver of the motor vehicle in an appropriate manner. Background Technology

[0002] In addition to service braking systems with friction brakes operated by a pressure medium, heavy commercial vehicles typically also have wear-free continuous brakes in the form of hydraulic or electric reducers, which allow the vehicle to decelerate without using friction brakes. When the reducer is used, the vehicle's kinetic energy is converted into heat, which is dissipated into the ambient air through suitable cooling equipment. The braking force of the reducer depends on the vehicle's speed or the rotational speed of the driveshaft, such as the output shaft of a gearbox, to which the reducer's rotor is connected. The available braking force of the reducer is limited by the heat that can be dissipated, which may necessitate engaging friction brakes to prevent overheating. Furthermore, vehicles with reducers cannot be brought to a complete stop; therefore, friction brakes must be engaged no later than reaching or falling below the minimum operating speed.

[0003] With the increasing electrification of vehicles, commercial vehicles, whether pure electric or hybrid, are also equipped with at least one motor. This motor is connected to the wheels on the axle and functions as both a motor and a generator, and therefore can also act as a wear-free continuous brake during generator operation. During generator operation, the vehicle's kinetic energy is converted into electrical energy, which can be used to charge the energy storage device in so-called regenerative operation. The available braking force in the motor is limited by both the heat that can be dissipated and the capacity of the energy storage device; therefore, it may be necessary to engage a reduction gear and / or friction brake to prevent overheating of the motor or overcharging of the energy storage device.

[0004] In an electronically controlled braking system with an integrated continuous braking system of the type just described, the braking request requested by the driver via deflection of the brake pedal and detected by a brake value transmitter located on the foot brake valve is allocated to the braking system based on a predetermined priority order and current operating parameters, such as vehicle speed, operating temperature of the reducer or motor, and charging status of the energy storage device (Brake Blending). Here, the priority order is typically defined such that, during braking, the motor is first put into generator operation to decelerate the vehicle in order to charge the energy storage device; then, the reducer is engaged if needed; and finally, the service brake system with friction brakes is used to decelerate the vehicle if needed. Because the driver of the motor vehicle expects the change in resistance acting on the brake pedal to be the same regardless of how the braking force is allocated to the aforementioned components of the braking system, a brake pedal actuator is usually present, which generates a restoring force and introduces it into the brake pedal. The reset force is measured to be such that it, together with the resistance generated in the foot brake valve, such as the spring force of the reset spring acting on the brake pedal and / or the squeezing force of the pressure medium acting on the control piston, forms a resistance acting on the brake pedal equivalent to the entire braking force.

[0005] A braking system for a hybrid vehicle is known from DE 11 2007 000 071 B4, comprising a service brake system with a hydraulically actuated friction brake, an electric motor connected to the wheels of the axle and capable of operating as a motor and generator, a foot brake valve operable via a brake pedal, and a brake value transmitter configured as a pressure sensor connected to the main braking circuit. The hybrid vehicle's drive system has an internal combustion engine coupled to an electric generator. The hybrid vehicle is driven by the electric motor during motor operation and braked during generator operation. During generator operation, the electrical energy generated by the electric motor is converted into heat in a radiator and released into the ambient air. During braking, the hybrid vehicle decelerates by the deflection of the brake pedal, in addition to deceleration via the friction brake of the service brake system, and also by deceleration via the electric motor operating as a generator. Conversely, during braking when the brake pedal deflection is small, the hybrid vehicle is configured to brake only using the friction brake of the service brake system to ensure precise quantification of braking force.

[0006] US 2004 / 0251095 A1 describes a braking system for an electric vehicle, comprising a service brake system with a hydraulically actuated friction brake, a motor capable of operating as a motor and generator and being driven to the wheels of the axle, a main brake valve operable via a brake pedal, a brake value transmitter disposed on a brake lever of the brake pedal, and a brake pedal actuator for generating a restoring force acting on the brake pedal. In a first embodiment, the brake pedal actuator is configured as an electric motor, which is in an adjustable connection with the brake lever via a rack and pinion mechanism. In a second embodiment, the brake pedal actuator is configured as a hydraulic or pneumatic adjusting cylinder, the piston rod of which is in an adjustable connection with the brake lever. During braking, the braking force requested by the deflection of the brake pedal is distributed between the friction brake of the service brake system and the motor operating as a generator. Here, a restoring force is generated by the brake pedal actuator and directed into the brake lever. This restoring force is equivalent to the portion of the braking force generated by electricity, so that the restoring force perceived by the driver on the brake pedal is the same as that perceived during braking caused by pure hydraulic pressure.

[0007] DE 10 2012 209 157 A1 discloses a braking system for an electric or hybrid vehicle, comprising a service brake with a friction brake operable by a pressure medium, at least one motor connected in drive to a wheel on the axle and capable of operating as a motor and generator, and a foot brake valve operable by means of a brake pedal, the foot brake valve having a brake value transmitter and a brake pedal actuator for generating a reset force acting on the brake pedal. During braking, the vehicle first decelerates via the motor operating as a generator. Before the motor reaches its maximum braking torque, the service brake with the friction brake is activated. In the adjustment device, the reset force is determined based on the deflection of the brake pedal and the maximum, currently available, or non-regenerated braking torque of the motor, and this reset force is adjusted by means of the brake pedal actuator. Before the motor reaches its maximum braking torque, the service brake with the friction brake is engaged, and the increased reset force on the brake pedal informs the vehicle driver of this situation.

[0008] A foot brake valve for an electronically controlled compressed air braking system is known from DE 10 2018 114 848 A1. This foot brake valve has a brake value transmitter configured as a displacement sensor and an electro-actuated brake pedal actuator for generating a reset force acting on the brake pedal. The brake pedal actuator is flanged to the foot brake valve housing adjacent to a spring plate via an open pressure chamber (which can be inflated via an inlet valve and vented via an outlet valve). The spring plate is axially movable within the foot brake valve housing and primarily supports the reset spring, against which an axially movable tappet piston rests. A gradually or progressively increasing reset force can be introduced into the brake pedal via the brake pedal actuator. During braking with ABS activated, pressure pulses can be introduced into the brake pedal via the brake pedal actuator; these pressure pulses are perceptible to the driver as vibrations and should indicate that ABS is currently active.

[0009] In motor vehicles equipped with a service braking system with friction brakes, a reduction gear, and at least one motor capable of operating as a generator, the distribution of braking force to the components of the braking system can be displayed to the driver, for example, on a display in the instrument panel, during braking. The driver can then influence the braking process by manipulating the brake pedal, thereby, for example, avoiding the operation of the friction brakes of the service braking system, and thus preventing wear on the friction pads, brake discs, or brake drums. However, since the driver should not take their eyes off the traffic space ahead during sudden braking to keep the vehicle in the lane, prevent collisions with other vehicles, or avoid obstacles, it is also desirable to have tactile feedback on the brake pedal regarding the current distribution of braking force. Summary of the Invention

[0010] Therefore, the object of the present invention is to provide a method for controlling the braking system of a motor vehicle of the type described above, by which the driver's braking intention can be appropriately communicated to the components of the braking system. Furthermore, a braking system in which the mentioned method can be operated is shown and described.

[0011] The solution to the task related to the method is achieved by the method for controlling the braking system of a motor vehicle according to the present invention. The present invention solves the equipment-related task through the braking system of a motor vehicle according to the present invention.

[0012] The claim seeks to protect a braking system for a motor vehicle comprising a service braking system with a friction brake operable by a pressure medium, a continuous braking system configured as a hydraulic or electric reducer, at least one motor connected in transmission to a wheel on an axle and capable of operating as a generator, and a foot brake valve operable by means of a brake pedal, wherein the foot brake valve has a brake value transmitter and a brake pedal actuator for generating a reset force acting on the brake pedal, and wherein all the aforementioned components of the braking system are controllable by means of an electronic controller, wherein a signaled braking force request is satisfied in priority in the order of the motor operating as a generator, the reducer, and the service braking system, and wherein the distribution of braking force to the components of the braking system is communicated to the driver of the motor vehicle in an appropriate manner.

[0013] To address equipment-related tasks, the braking system includes an electrically operated brake pedal actuator with a rotatable or axially movable drive element. The drive element of the brake pedal actuator is directly or indirectly connected to the brake lever of the brake pedal or to the tappet piston of the foot brake valve.

[0014] In one preferred embodiment, braking force is signaled by deflection of the brake pedal. In another preferred embodiment, braking force request is automatically signaled via electronically calibrated braking request. For example, in advanced braking systems such as ESP (Electronic Stability Program), ESC (Electronic Stability Control), and ASR (Anti-Slip Regulation), vehicle deceleration and / or braking force request can be controlled or calibrated independently of the driver's braking intention provided by deflection of the brake pedal.

[0015] Compared to the hydraulic or pneumatic regulating cylinders known in the prior art, brake pedal actuators constructed in an electrically actuated manner have the advantages of better or faster response characteristics and more precise quantification of the reset force and the signal force affecting the brake pedal.

[0016] According to the first improved embodiment of the braking device, the brake pedal actuator is configured as an electric motor with a rotatable rotor shaft. Here, the rotor shaft of the electric motor is directly or indirectly connected to the brake lever of the brake pedal or to the tappet piston of the foot brake valve via a lead screw drive.

[0017] Alternatively, the brake pedal actuator can be configured as an electromagnet with an armature capable of axial movement, wherein the armature of the electromagnet is directly or indirectly in an adjusting connection with the brake lever of the brake pedal or with the tappet piston of the foot brake valve.

[0018] Therefore, the present invention first relates to a method for controlling a braking system of a motor vehicle, the braking system comprising a service braking system with a friction brake operable by a pressure medium, a continuous braking system configured as a hydraulic or electric reducer, at least one motor that is in transmission connection with a wheel on an axle and can operate as a generator, and a foot brake valve operable by means of a brake pedal, wherein the foot brake valve has a brake value transmitter and a brake pedal actuator for generating a reset force acting on the brake pedal, and wherein all the aforementioned components of the braking system are controllable by means of an electronic controller, wherein a braking force request indicated by a deflection signal of the brake pedal is satisfied in priority in the order of the motor, reducer, and service braking system operating as a generator, and wherein the distribution of braking force to the components of the braking system is informed to the driver of the motor vehicle in an appropriate manner.

[0019] To address the task related to the method, the braking device is equipped with a system in which, when the distribution of braking force to the components of the braking device changes at least once, a tactilely perceptible signal force is briefly superimposed on the reset force acting on the brake pedal by means of a brake pedal actuator.

[0020] The advantage here is that the driver is informed of the change in the distribution of braking force to the components of the braking system only for a very short period of time; that is, the driver does not feel a continuous change in the restoring force acting on the brake pedal. Because this information is conveyed separately to the driver's foot via the brake pedal, the driver can keep their eyes focused on the traffic space ahead.

[0021] According to a first improvement of the described method, when at least one component of the braking system is engaged or disengaged, a tactilely perceptible signal force is briefly superimposed on the restoring force acting on the brake pedal by means of the brake pedal actuator. The aforementioned advantages also apply to variations of the method. However, in the improved method, the driver is only informed of this information by means of an additional signal force acting on the brake pedal when one component of the braking system is fully engaged or fully disengaged.

[0022] By generating a tactilely perceptible signal force through the brake pedal actuator and introducing it into the brake pedal, the driver of the motor vehicle is informed of the recent or ongoing change in the distribution of braking force to the components of the braking system. For example, this could be informing the driver that the motor is engaged or disengaged from its generator operation, or that the decelerator or service brakes are engaged or disengaged. Because this information is signaled to the driver via the brake pedal to their foot, the driver does not need to take their eyes off the road ahead to receive the information. In response to the signal force, the driver can influence the distribution of braking force to the aforementioned components of the braking system by correspondingly manipulating the brake pedal. Therefore, for example, during electric braking while the motor is engaged from its generator operation, the driver can meaningfully prevent the decelerator from engaging by slightly releasing the brake pedal, provided traffic conditions allow for a lower braking deceleration.

[0023] In this regard, it may be advantageous to make the current distribution of braking force to the components of the braking system perceptible by making the signal force that changes the reset force acting on the brake pedal function as a pulse-like increase in the reset force.

[0024] To enable differentiation between the on and off states of the braking system components during braking, it is preferable that the pulsed signal forces triggered by different changes in braking force distribution differ in quantity and / or intensity and / or duration. This will be further discussed in the description of one embodiment.

[0025] According to another variation of the method, the signal force is triggered in the form of a sequence of multiple oscillations, including a restoring force, that act as a perceptible vibration on the brake pedal. In this embodiment of the signal force, the oscillation sequence triggered may vary in frequency and / or amplitude and / or duration depending on different changes in the distribution of the braking force.

[0026] Clearly, the aforementioned method variations can also be used in combination, for example, such that the on / off status of at least one component of the braking system, such as a generator-operated motor, is signaled via at least one pulsed, amplified signal force in the form of a reset force. In contrast, the on / off status of other components of the braking system, such as a service brake system with friction brakes, is communicated to the driver via a signal force in the form of a perceptible vibration sequence including a reset force. Attached Figure Description

[0027] The method and braking device having the features of the present invention will now be described intuitively with reference to the embodiments shown in the accompanying drawings. In the drawings: Figure 1A schematic view shows a motor vehicle with a braking system that has the features of the present invention, and Figure 2 A force-time graph is shown, which visually illustrates the changes in the braking process when the control method according to the invention is applied. Detailed Implementation

[0028] Figure 1 The illustrated motor vehicle 2 (which is a commercial vehicle) has a front axle 4 with single tires and two wheels 6a and 6b, and a rear axle 8 with dual tires and, for example, four wheels 10a, 10a', 10b, and 10b'. The motor vehicle 2 can be selectively or jointly driven by an internal combustion engine 12 and / or by an electric motor 24 that can selectively operate as a motor or generator. The internal combustion engine 12 is driven to the wheels 10a, 10a', 10b, and 10b' of the rear axle 8 via a disengagement clutch 14, a shift transmission 16, a universal joint 18, a first axle differential 20, and one drive axle 22a, 22b. The electric motor 24 is driven to the wheels 6a and 6b of the front axle 4 via a drive shaft 26, a second axle differential 28, and one drive axle 30a, 30b. During motor operation, the electric motor 24 is supplied with electrical energy by an associated energy storage device 32. In generator operation, motor 24 is preferably used to charge energy storage device 32.

[0029] The braking system 34 of the motor vehicle 2 is electronically controllable, and in addition to the electronic controller 36, it also includes a service braking system 38 with wheel brakes 40a, 40b, 42a, 42b that are friction brakes and can be operated by a pressure medium; a secondary brake 44 in the form of a continuous braking system or a hydraulic or electric reducer; a motor 24 that is driven to the wheels 6a, 6b of the front axle 4; and a foot brake valve 48 that can be operated by means of the brake pedal 46. The foot brake valve can be directly or indirectly connected to a brake value transmitter 50, which is implemented as an adjustment displacement sensor, and a brake pedal actuator 52. The brake pedal actuator 52 is used to generate a restoring force acting on the brake pedal 46. For operation, the brake pedal actuator is connected to the electronic controller 36 via an electrical control circuit 54.

[0030] A drive element 53 that acts axially or rotatably is arranged on the brake pedal actuator 52, through which a signal force can be applied to the brake pedal 46 in addition to the aforementioned reset force.

[0031] The service braking system 38 is implemented as a compressed air braking system, and has a compressed air supply device 56 and two braking circuits 58 and 60. The compressed air supply device 56 includes a compressor 62, a pressure regulator 64, and a multi-circuit protection valve 66. The compressor 62 can be driven by the internal combustion engine 12. Compressed air is transported to the two braking circuits 58 and 60 via the compressor 62, pressure regulator 64, and multi-circuit protection valve 66.

[0032] The first braking circuit 58 has a first pressure storage 70 and a first reserve line 68 leading from the multi-circuit protection valve 66 to the foot brake valve 48. A first axle braking line 72 is connected to the foot brake valve 48, and braking pressure is actuated by the brake pedal 46 in this first axle braking line. The first axle braking line 72 leads to a first axle valve module 74 on the rear axle 8.

[0033] The first axle valve module 74 includes a relay valve and preferably includes ABS valve assemblies (not shown) in each wheel pair 10a, 10a'; 10b, 10b' of the rear axle 8. It should be noted that the presence of the ABS valve assembly in the first axle valve module 74 is only an optional implementation, especially when the first axle valve module 74 is configured as an electronically operable valve module. Wheel braking lines 76a, 76b are respectively guided from the first axle valve module 74 to the corresponding wheel brakes 42a, 42b of the rear axle 8. The relay valve of the first axle valve module 74 is primarily electronically controlled by means of the brake value transmitter 50 of the foot brake valve 48. For this purpose, the brake value transmitter 50 is connected to the electronic controller 36 via the electrical sensor line 78 and the first axle valve module 74 via the electrical control line 80. In a redundant configuration, i.e., in the event of electronic control failure, the relay valve of the first axle valve module 74 is pneumatically controlled by the braking pressure applied in the axle braking line 72.

[0034] The second braking circuit 60 has a second reserve line 82 and a second pressure storage 84, wherein the second reserve line 82 is guided from the multi-circuit protection valve 66 to the foot brake valve 48 via the second pressure storage 84. The second axle braking line 86 extends from the foot brake valve 48 to the second axle valve module 88, where braking pressure is triggered by the actuation of the brake pedal 46. The second axle valve module 88 also includes a relay valve (not shown) and ABS valve assemblies in each wheel 6a, 6b of the front axle 4. Wheel braking lines 90a, 90b are guided from the ABS valve assemblies of the second axle valve module 88 to the corresponding wheel brakes 40a, 40b of the front axle 4. The relay valves of the second axle valve module 88 are also primarily electronically controlled based on the braking value detected by the brake value transmitter 50 of the foot brake valve 48, and are connected to the electronic controller 36 via electrical control line 92 for this purpose. In the redundant case, the relay valve of the second axle valve module 88 also relies on the braking pressure applied in the second axle braking line 86 for pneumatic control.

[0035] The reducer 44 is driven to the output shaft of the shift transmission 16, and is also driven to the wheels 10a, 10a', 10b, and 10b' of the rear axle 8 via the universal joint 18, axle differential 20, and drive shafts 22a and 22b. For electronic control, the reducer 44 is connected to the electronic controller 36 via electrical control circuit 94. The motor 24 is also connected to the electronic controller 36 via electrical control circuit 96.

[0036] During braking, the driver's desired braking deceleration (which corresponds to the braking value detected by the braking value transmitter 50 when the brake pedal 46 is actuated) is distributed in the electronic controller 36 to the components of the braking system 34. As mentioned, these components are the service brake system 38, the reducer 44, and the motor 24 in generator operation, wherein the braking force is distributed in a priority order of motor 24, reducer 44, and service brake system 38.

[0037] Thus, vehicle 2 is first braked without wear using motor 24, which operates as a generator, while the kinetic energy of vehicle 2 is partially recovered and charged (regenerated) to the energy storage 32. Subsequently, vehicle 2 continues to brake without wear with decelerator 44 before operating the friction brakes 40a, 40b, 42a, 42b of service brake system 38. In a preferred embodiment, it can also be proposed that the allocation or process planning, sequencing, or prioritization of braking force usage with respect to the aforementioned braking components (service brake system 38, decelerator 44, and motor 24 operating as a generator) depends on the driver's intended braking intention (e.g., determined by electronic controller 36). Because regardless of how the braking force is distributed to the components 24, 38, 44 of brake system 34 during a specific deflection of brake pedal 46, the driver should perceive the most similar resistance F on brake pedal 46. BP Therefore, in a preferred embodiment, a reset force in the form of a corresponding signal force is generated on the brake pedal actuator 52 by means of a drive element 53 that acts axially or rotationally, and is introduced into the brake pedal 46.

[0038] In another preferred embodiment, when the driver should or must be informed of the distribution of braking force to components 24, 38, 44 during a specific deflection of the brake pedal 46 or foot brake valve 48, feedback to the driver is provided by an increased sense of resistance or deflection on the brake pedal 46 or foot brake valve 48. It should be considered that the deflection of the brake pedal 46 does not always reflect the desired vehicle deceleration. For example, in advanced braking systems such as ESP (Electronic Stability Program), ESC (Electronic Stability Control), and ASR (Anti-Slip Regulation), vehicle deceleration and / or braking force requests can be controlled independently of the driver's braking intention.

[0039] In order to inform the driver, in addition to optical display in the instrument panel of the vehicle 2, of the distribution of braking force to components 24, 38, and 44 of the braking device 34 when necessary, information regarding the allocation of braking force to components 24, 38, and 44 of the braking device 34 is provided according to the invention, when the allocation of braking force to components 24, 38, and 44 of the braking device 34 changes at least once, for example, when one of components 24, 38, and 44 of the braking device 34 is engaged and / or disengaged, a brief, tactile signal force perceptible to the driver's foot is superimposed on the reset force by means of the brake pedal actuator 52. Figure 2 The diagram illustrates, for example, how this should preferably be done.

[0040] exist Figure 2 The graph shows the resistance F acting on the brake pedal 46 during the braking process. BP Regarding the change process over time t (F)BP (t)). Resistance F BP The braking force is the sum of the resistance generated within the foot brake valve 48 and the restoring force induced by the foot brake actuator 52. The braking process begins at time t0 by the driver's operation of the brake pedal 46, wherein the vehicle 2 initially decelerates solely through the motor 24, which operates as a generator. At time t1, the decelerator 44 is engaged, which is indicated to the driver by a pulse-shaped, enhanced signal force S1 that is tactilely perceptible in the form of a restoring force having an intensity H1 and a duration T1.

[0041] Then, the braking torque of motor 24 continues to decrease, and the braking torque of reducer 44 increases accordingly, until motor 24 is completely turned off at time t2. The turning off of motor 24 is communicated to the driver by a double-pulse signal force S2, which is tactilely perceptible and has a resetting force of intensity H2 and duration T2. ​​Currently, by example, the intensity H2 of the second signal force S2 can be identified as being less than the intensity H1 of the first signal force S1, and the duration T2 of the second signal force S2 can be identified as being greater than the duration T1 of the first signal force S1 (H2). T1). Turning off the motor 24 and turning on the reducer 44 may be necessary, for example, because the energy storage 32 is fully charged and / or the motor 24 has reached its overheat limit.<h1>

[0042] At time t3, the service braking device 38, equipped with friction brakes 40a, 40b, 42a, and 42b, is activated, and is displayed to the driver via a signal force S3 that is perceptible to the touch as a sequence of multiple oscillations including a restoring force (with amplitude A1, frequency f1, and duration T3). Then, the braking torque of the decelerator 44 continuously decreases, and the braking torque of the friction brakes 40a, 40b, 42a, and 42b increases accordingly by increasing the induced braking pressure, until the decelerator 44 is completely deactivated at time t4.

[0043] The decelerator 44 is turned off by signal force S4, which is perceptible to the driver in the form of a tactilely perceptible oscillation sequence (with amplitude A2, frequency f2 and duration T4) of multiple oscillations including a reset force.

[0044] Currently, by way of example, the amplitude A2 of the fourth signal force S4 is greater than the amplitude A1 of the third signal force S3, the frequency f2 of the fourth signal force S4 is less than the frequency f1 of the third signal force S3, and the duration T4 of the fourth signal force S4 is less than the duration T3 of the third signal force S3 (A2>A1, f2<f1, T4<T3). Deactivating the retarder 44 and activating the service braking facility 38 may be necessary, for example, because the retarder 44 is no longer able to generate an available braking torque and / or has reached its overheating limit as the driving speed of the motor vehicle 2 decreases.

[0045] By means of the signal forces S1, S2, S3, S4, which are superimposed on the restoring force and induced into the brake pedal 46 by the drive element 53 on the brake pedal actuator 52, the driver is informed of the corresponding processes for distributing the braking force, such as how to activate the retarder 44 or the service braking facility 38, or deactivate the electric motor 24 or the retarder 44, without the driver having to take their eyes off the traffic space ahead of them. By configuring the signal forces S1, S2, S3, S4 differently, the respective activation and deactivation processes can be clearly identified. If there is no emergency braking, the driver can influence the distribution of braking force to the components 24, 38, 44 of the braking facility 38 via actuating the brake pedal 46, for example, in that the driver causes a return to the previous braking force distribution by partially releasing the brake pedal 46.

[0046] List of reference signs (part of the description)

[0047] 2 motor vehicle, commercial vehicle

[0048] 4 axle, front axle

[0049] 6a, 6b wheels on the front axle

[0050] 8 axle, rear axle

[0051] 10a, 10a' wheel on the right side of the vehicle on the rear axle

[0052] 10b, 10b' wheel on the left side of the vehicle on the rear axle

[0053] 12 internal combustion engine

[0054] 14 separating clutch

[0055] 16 gear shift transmission

[0056] 18 cardan shaft

[0057] 20 axle differential on the rear axle

[0058] 22a, 22b drive shafts on the rear axle

[0059] 24 motors

[0060] 26 Drive shaft

[0061] 28. Axle differential on the front axle

[0062] Drive shafts on the front axles of 30a and 30b

[0063] 32. Energy storage devices, batteries

[0064] 34 Braking system

[0065] 36 Electronic Controller

[0066] 38. Service Braking System

[0067] Wheel brakes and friction brakes on the front axles of vehicles 40a and 40b

[0068] Wheel brakes and friction brakes on the rear axles of vehicles 42a and 42b

[0069] 44. Continuous braking system, speed reducer

[0070] 46. ​​Brake pedal

[0071] 48 Foot brake valve

[0072] 50 Braking value transmitter, adjustable displacement sensor

[0073] 52 Brake pedal actuator

[0074] 53. Drive element on brake pedal actuator

[0075] 54 First Control Line

[0076] 56 Compressed air supply unit

[0077] 58 First Braking Circuit

[0078] 60 Second Braking Circuit

[0079] 62 Compressor

[0080] 64 Pressure Regulator

[0081] 66 Multi-circuit protection valve

[0082] 68 First Reserve Line

[0083] 70 First pressure storage device

[0084] 72 First axle braking circuit

[0085] 74 First Axle Valve Module

[0086] 76a and 76b wheel brake circuits

[0087] 78 Second sensor circuit

[0088] 80 Third Control Circuit

[0089] 82 Second Reserve Line

[0090] 84 Second pressure storage device

[0091] 86 Second axle braking circuit

[0092] 88 Second axle valve module

[0093] 90a and 90b wheel braking circuits

[0094] 92 Fourth Control Circuit

[0095] 94 Fifth Control Circuit

[0096] 96 Sixth Control Circuit

[0097] A1 Amplitude of signal force S3

[0098] Amplitude of signal force S4 (A2)

[0099] ECU (Electronic Control Unit)

[0100] f1 signal force S3 frequency

[0101] f2 signal force S4 frequency

[0102] F BP resistance

[0103] H1 signal strength S1

[0104] The strength of signal force S2 (H2)

[0105] S1 signal force, improved reset force

[0106] S2 signal force, improved reset force

[0107] S3 signal strength, oscillation sequence

[0108] S4 signal strength, oscillation sequence

[0109] t time

[0110] t0 is the start time point.

[0111] t1 First time point

[0112] T1 is the duration of signal force S1.

[0113] t2 Second time point

[0114] T2 is the duration of the signal force S2.

[0115] t3 Third time point

[0116] T3 is the duration of signal force S3.

[0117] t4 Fourth Time Point

[0118] T4 signal force S4 duration

Claims

1. A braking system (23) for a motor vehicle (2), the braking system comprising a service braking system (38) with friction brakes (40a, 40b, 42a, 42b) operable by a pressure medium, a continuous braking system (44) configured as a hydraulic or electric reducer, at least one motor (24) that is in transmission connection with a wheel (6a, 6b) on an axle (4) and can operate as a generator, and a foot brake valve (48) operable by means of a brake pedal (46), wherein, The foot brake valve (48) has a brake value transmitter (50) and a brake pedal actuator (52) for generating a reset force acting on the brake pedal (46), wherein the motor (24) of the braking device (23), the service brake device (38) and the continuous braking device (44) can be controlled by means of an electronic controller (36), wherein the braking force request is requested in priority in the order of the motor (24) in generator operation, the reducer and the service brake device (38), and wherein the braking force is applied to the... The distribution of the motor (24), service brake (38) and continuous braking (44) of the braking device (23) can be communicated to the driver of the motor vehicle (2) in an appropriate manner. The brake pedal actuator (52) is electrically constructed and has a rotatable or axially movable drive element (53). The drive element (53) of the brake pedal actuator (52) is directly or indirectly connected to the brake lever of the brake pedal (46) or to the tappet piston of the foot brake valve (48).

2. The braking device according to claim 1, characterized in that, The brake pedal actuator (52) is configured as an electric motor with a rotatable rotor shaft, and the rotor shaft of the electric motor is directly or indirectly connected to the brake lever of the brake pedal (46) or to the tappet piston of the foot brake valve (48) via a screw drive.

3. The braking device according to claim 1, characterized in that, The brake pedal actuator (52) is constructed as an electromagnet with an armature that can move axially, and the armature of the electromagnet is directly or indirectly in an adjustable connection with the brake lever of the brake pedal (46) or in an adjustable connection with the tappet piston of the foot brake valve (48).

4. The braking device according to any one of claims 1 to 3, wherein, The braking force request is signaled by means of the deflection of the brake pedal (46).

5. A method for controlling a braking device (34) of a motor vehicle (2), said braking device comprising a service braking device (38) with friction brakes (40a, 40b, 42a, 42b) operable by a pressure medium, a continuous braking device (44) configured as a hydraulic or electric reducer, at least one motor (24) that is in transmission connection with a wheel (6a, 6b) on an axle (4) and is capable of operating as a generator, and a foot brake valve (48) operable by means of a brake pedal (46), wherein, The foot brake valve (48) has a brake value transmitter (50) and a brake pedal actuator (52) for generating a reset force acting on the brake pedal (46), wherein the motor (24), service brake (38), and continuous braking (44) of the braking device (34) can be controlled by means of an electronic controller (36), wherein braking force requests are satisfied in priority order of the motor (24) in generator operation, the reducer, and the service brake (38), and wherein the braking force is applied to the brake... The driver of the motor vehicle (2) is informed in an appropriate manner of the distribution of the motor (24), service brake system (38) and continuous braking system (44) of the facility (34), characterized in that when the distribution of braking force to the motor (24), service brake system (38) and continuous braking system (44) of the braking system (34) changes at least once, a tactilely perceptible signal force (S1, S2, S3, S4) is briefly superimposed on the reset force acting on the brake pedal (46) by means of the brake pedal actuator (52).

6. The method according to claim 5, characterized in that, When at least one of the motor (24), service brake (38) and continuous braking (44) of the braking device (34) is turned on or off, a tactilely perceptible signal force (S1, S2, S3, S4) is briefly superimposed on the reset force acting on the brake pedal (46) by means of the brake pedal actuator (52).

7. The method according to claim 5 or 6, characterized in that, The signal forces (S1, S2) that change the reset force act as an increase in the reset force by at least one pulse shape.

8. The method according to claim 7, characterized in that, When the distribution of braking force changes, the pulse-shaped signal forces (S1, S2) that are triggered differ from each other in terms of their quantity and / or intensity (H1, H2) and / or duration (T1, T2).

9. The method according to claim 5 or 6, characterized in that, The signal forces (S3, S4) are triggered in the form of an oscillation sequence of multiple oscillations, including a reset force, which can be perceived as vibration on the brake pedal (46).

10. The method according to claim 9, characterized in that, The oscillation sequences triggered by different changes in the distribution of braking force differ from each other in terms of frequency (f1, f2) and / or amplitude (A1, A2) and / or duration (T3, T4).

11. The method according to claim 5 or 6, characterized in that, The braking force request is signaled by the deflection of the brake pedal (46).

Images