DE102016221622A1 - Method and device for providing a braking effect of a motor vehicle - Google Patents

Abstract

The invention relates to a method for providing a braking effect in a motor vehicle (1), in particular in the context of cooperative braking, wherein the motor vehicle (1) has a braking device with a friction brake (10) and with an engine brake for braking the motor vehicle (1), wherein a braking effect of the engine brake is composed of a plurality of individual braking effects (E1, E2, ..., En) based on a plurality of braking mechanisms, comprising the steps of: assigning priorities (P1, P2, ..., Pn) to the Single brake actions (E1, E2, ..., En) of the engine brake, selecting at least one of the individual brake actions (E1, E2, ..., En) according to the assigned priorities (P1, P2, ..., Pn), andactivating the Engine brake by implementing the selected single braking action (E1, E2, ..., En) for providing the braking effect, in particular from a higher-level control unit, in particular from an ABS / ESP control unit (15b) of the control unit (15) is required, in particular, the requested braking effect of one of an engine control unit (15 a) of the control unit (15) cyclically maximum to be set total engine braking action is limited, which is determined in particular based on implemented models.

Description

Technical area

The invention relates to motor vehicles, and in particular measures for providing a braking effect in a motor vehicle, wherein the motor vehicle has a reciprocating internal combustion engine, a friction brake and an engine brake for braking the motor vehicle.

State of the art

For braking, motor vehicles have service brake devices with friction brakes. Friction brakes are technical systems for the longitudinal deceleration of a motor vehicle. The entirety of transmission and control equipment is referred to as a brake system. In the usual braking process, the kinetic energy (kinetic energy) of the motor vehicle is converted into heat energy by friction or adequate processes and dissipated (energy loss). Recent techniques allow the conversion of kinetic energy into electrical energy and their storage by recuperation with a regenerative brake.

While in the conventional braking of a motor vehicle with the friction brake, the braking energy of the vehicle is thus converted into heat and lost, as much braking energy is recovered with a regenerative brake and stored as electrical energy. To decelerate the motor vehicle, e.g. used a generator. The friction brake is only used when the brake request exceeds the brake potential of the regenerative brake - such. B. also during the stopping process.

This is from the publication DE 196 04 134 A1 a method and a device for controlling a brake system of a motor vehicle with electric drive known, wherein the braking torque is applied in a first region of the driver's braking request almost exclusively by the regenerative braking, while the friction brake substantially does not contribute to the braking effect. This is realized in that, in this region of the braking request, the pressure medium flowing into the wheel brake cylinders from the driver by the brake pedal actuation is returned by appropriate control into a storage chamber.

However, the engine drag torque remains unused to decelerate the vehicle. Here, the engine drag torque is understood to mean a torque that is necessary to externally drive an unfired reciprocating internal combustion engine, i. to overcome its internal friction forces. In conventional vehicle system architectures, (slight) engine braking torques have already been activated which are predefined purely in accordance with drivability criteria (= comfort). Unused is the largely freely configurable engagement behavior when it comes to safety issues (higher braking requirements) and when an overall vehicle system with multiple braking devices is to optimize overall. Here the engine brake can make another contribution. In this case, basic reconciliations can be maintained and further variable braking contributions can be switched on depending on the situation.

Disclosure of the invention

According to the invention, a method for providing a braking effect in a motor vehicle according to claim 1 and a device according to an independent claim are provided.

Further embodiments are specified in the dependent claims.

According to a first aspect, a method is provided for providing a braking effect in a motor vehicle, in particular in the context of cooperative braking, wherein the motor vehicle has a braking device with a friction brake and with at least one engine brake for braking the motor vehicle, and wherein a braking effect of the engine brake itself is composed of a plurality of single-brake actions based on a plurality of brake mechanisms. The procedure provides that
Priorities are assigned to the individual brake effects of the engine brake,
at least one of the individual braking effects is selected according to the assigned priorities, and
the engine brake is activated by reacting the selected individual braking effects to provide the braking effect, which is requested in particular by a higher-level control unit, in particular by an ABS / ESP control unit of the control unit, wherein in particular the requested braking effect of one of an engine control unit of the control unit cyclically maximum total engine braking effect is limited, which is determined in particular based on implemented models.

One idea of the above method is to prioritize a plurality of different individual brake effects and then recall them according to their priorities as needed, so that they can be used as engine brakes in addition to the actual friction brake and optionally next to a regenerative brake, eg a hybrid drive. Thus, the individual braking effects, for example, by a prioritization according to the level of their respective braking effect and their temporal availability targeted be selected and activated. This makes it possible to provide a braking effect of the required strength and at the right time, without having to resort to the friction brake, provided that the engine brake can apply the requested braking torque alone. Improved and more efficient use of all existing brake systems is achieved, protecting individual brake systems from overstress and excessive wear.

In this way it is possible, for example, to use the engine drag torque to decelerate the motor vehicle. This allows the use of the friction brake and thus the wear of components of the friction brake, such as. brake linings of the friction brake, to reduce. Furthermore, an increased braking effect in the case of full or panic braking can be provided by the additional braking effect of the engine brake and thus the safety in road traffic can be increased.

According to one embodiment, it may be detected whether there is a frictional connection between a drive unit of the motor vehicle and a roadway, and activating the further engine brake to provide the braking effect is only on detection of a presence of a frictional connection between the drive unit of the motor vehicle and the roadway. This ensures that e.g. only with continuous adhesion, the engine brake is activated, because only with the clutch engaged, engaged gear and traction of the tire is a braking effect causing engine drag available, if the motor vehicle has a manual transmission with gears and a clutch. For the adhesion condition in an automatic transmission with converter clutch as well as in a motor vehicle with continuously variable transmission with infinite translation analog signals can be evaluated to determine whether a positive connection is present. With traction detection, the engine brake can be activated as required; thus the operational safety is increased.

According to a further embodiment, one of the individual brake effects may be variable, and when the engine brake is activated, the individual braking effect may be changed. To change the individual brake effects, parameters can be changed that change the engine drag torque. Thus, an adaptation of the individual brake effects to a requested overall braking effect or to a requested deceleration is possible.

According to a further embodiment, when assigning the priorities, the scalability of the values of the individual brake effects and / or the magnitude of the individual brake effects and / or the temporal nature of the individual brake effects and / or compensation measures to compensate for side effects of the individual brake effects may be required and / or if additional secondary effects are required. or lateral effects due to the individual brake effects and / or whether the individual brake effects cause damage and / or dynamics of the individual brake effects are taken into account. Thus, the amount of braking effect and its temporal availability, as well as the consequences of the individual braking effects are considered in the prioritization. Thus, a braking effect of desired height can be provided at the right time, but at the same time the risk of consequential damage, e.g. be minimized by overuse of components. In particular, it can be provided that the scalability or adjustability of the individual braking effect by changing variable parameters is taken into particular account during prioritization. For example, can be provided that only the single braking effect is assigned the highest priority, which is adaptable to a desired size via the variable parameters. This ensures an accurate implementation of a brake request.

According to another embodiment, a value for a height of a driver's braking request may be determined, and the value may be taken into account in assigning the priorities. Thus, a selection is made according to the amount of brake deceleration requested and it is ensured that this is provided as accurately as possible.

According to a further embodiment, individual brake effects can result from charge exchange losses of a drive unit of the motor vehicle and / or from a combustion process of an internal combustion engine of the motor vehicle and / or by a mechanical load of the motor vehicle and / or by an electrical load of the motor vehicle and / or by friction losses of a drive unit of the motor vehicle Motor vehicle and / or caused by an inertia of a drive unit of the motor vehicle.

The charge cycle losses may be due to intake side throttling, exhaust side throttling, camshaft timing, such as, e.g. Lift and / or phase, or based on a so-called. Jake brake. The individual brake effects based on changes in charge can be adjusted / varied by changing parameters.

Another single braking effect may be based on power consumption of mechanical consumers coupled to, ie driven by, the internal combustion engine, such as an air conditioning compressor. The increased power consumption of the air conditioning compressor can by a Reduction of heat exchange can be compensated, ie by a reduction in performance of a fan, so as not to affect the desired passenger compartment temperature. The individual braking effects based on mechanical consumers can be varied by changing parameters. Other single-brake effects may be due to power consumption of electrical loads that increase engine drag torque through increased power demand on a regeneratively powered electric machine or alternator. These may be an oil pump, a water pump, the generator itself, a radiator fan, a heater fan or an automatic air conditioning or disc heaters. An increased power of a water pump or a cooling fan can be compensated by closing a thermostat, such as an electrothermostat, to maintain the coolant temperature. In this case, based on electrical consumers individual braking effects can be varied by changing parameters. Finally, individual brake effects can also be caused by internal engine friction losses or by mechanical inertia of the rotating masses of the internal combustion engine. This may be, for example, a crankshaft, but also parts of the vehicle transmission in the rotating masses. In this case, based on internal engine friction losses individual braking effects can be varied indirectly by changing parameters, such as an engine speed over a transmission ratio.

According to a further embodiment, a higher-level control unit (master control unit) of the motor vehicle, in particular an ABS / ESP control unit of the control unit, can direct a braking request to the engine brake within the scope of its potential. This is a feedback size of the engine control to the master control unit and it includes the sum of all currently possible maximum individual braking contributions of the reciprocating internal combustion engine or the engine brake. So no other control units are needed, but it can be used already existing control units. In this case, e.g. an ABS / ESP control unit is designed to transmit braking contributions according to a driving dynamics situation to individual wheels of the motor vehicle.

According to another embodiment, an engine control unit may associate the priorities with the individual brake effects and select at least one of the individual brake actions according to the assigned priorities and activate the engine brake by implementing the selected single brake action to provide the braking effect. The selection of concrete individual brake effects to implement the requested by the ABS / ESP control unit engine braking torque is therefore responsible for the engine control according to the individual priorities assigned there. With decreasing priority level, further individual brake effects are added until the external requirement is fulfilled. Fine tuning takes place via variable motor control parameters. So there is a data exchange between the ABS / ESP control unit and the engine control unit instead.

According to a further embodiment, an engine control unit of the control unit can determine a level of at least one of the individual brake effects from model approaches. These describe the behavior of a reciprocating internal combustion engine as a function of variable input parameters of the reciprocating internal combustion engine and thus also allow an estimate of the height of the respective individual brake effects.

In another embodiment, a mathematical model may be used to determine braking effects of the single brake contributions based on the engine operating parameters. Thus, the braking effects of the individual components can be determined in a simple manner without additional sensors.

According to a further embodiment, the models can be implemented on a control unit of the motor vehicle, in particular an engine control unit.

According to a further aspect, a device for providing a braking effect in a motor vehicle, with a friction brake and with an engine brake for braking the motor vehicle is provided. Furthermore, the invention includes a computer program which, when executed in a data processing device, is adapted to carry out all the steps of such a method and a machine-readable storage medium on which such a computer program is stored.

list of figures

• 1 eine schematische Darstellung eines Kraftfahrzeugs mit einem Antriebsstrang und einer Bremsvorrichtung;
• 2 weitere Komponenten des in 1 gezeigten Kraftfahrzeugs in schematischer Darstellung, und
• 3 ein Flussdiagramm zur Veranschaulichung eines Verfahrens zur Bestimmung eines Motorbremsmoments in dem in 1 dargestellten Kraftfahrzeug.

Embodiments are explained below with reference to the accompanying drawings. Show it:

• 1 a schematic representation of a motor vehicle with a drive train and a braking device;
• 2 other components of in 1 shown motor vehicle in a schematic representation, and
• 3 a flowchart for illustrating a method for determining an engine braking torque in the in 1 illustrated motor vehicle.

Description of embodiments

In 1 is a schematic representation of a motor vehicle 1 shown a drive unit 2 that has a powertrain 3 with driven wheels 4 is coupled. The powertrain 3 further comprises a coupling 5 and a vehicle transmission 6 , so that depending on the driver's request and operating conditions, a reduction can be set according to the selected gear. The vehicle transmission 6 can be designed for manual operation or as an automatic transmission. Furthermore, the vehicle transmission 6 instead of discrete translations in the form of gears also be designed for continuous speed conversion.

The drive unit 2 represents a drive torque corresponding to an operation amount (accelerator pedal position) of a travel control device 12 , eg in the form of an accelerator pedal. When removing the operation of the driving device 12 can the drive unit 2 be set so that this is a motor drag torque, ie a deceleration torque, via the drive train 3 on the driven wheels 4 transfers.

On the drive train 3 can be more mechanical or electrical consumers 7 be coupled, such as an alternator, an air conditioner, an oil pump and the like, which can be selectively activated to an increased engine drag torque to the drive train 3 impose, so that a corresponding braking effect is achieved.

Furthermore, a braking device is provided, which is a friction brake 10 has, for example, in the form of a disc brake or drum brake is formed. The friction brake 10 is with a brake actuator 11 coupled in the form of a brake pedal. The brake control device 11 and the friction brake 10 are coupled so that an increased actuation amount of the brake actuator 11 (eg travel of the brake pedal) is associated with a request for increased delay.

A control unit 15 In addition to other engine control functions, it may also implement a method of automatically providing additional braking mechanisms to an engine brake. In addition, the control unit 15 also control a regenerative brake. The control unit 15 can - as will also be described in detail later - have multiple controllers.

In 2 are other components of the motor vehicle 1 shown schematically.

The drive unit 2 has in the present embodiment, a hybrid drive system with an internal combustion engine 16 , such as a gasoline or diesel engine, and an electric motor 17 as further components, wherein the electric motor 17 can also be operated as a generator to be used as a regenerative brake. Alternatively, the drive unit 2 even just a combustion engine 16 exhibit.

Other components are brake pressure actuators 18 for actuating the friction brake 10 and control units of the control unit 15 , The control unit 15 has in the present embodiment, an engine control unit 15a , an ABS / ESP control unit 15b , a hybrid controller 15d and a transmission control unit 15c on. In particular, the engine control unit 15a and / or the ABS / ESP controller 15b and / or the hybrid controller 15d and / or the transmission control unit 15c may have hardware and / or software components for their functions.

The engine control unit 15a , the ABS / ESP control unit 15b , the hybrid controller 15d and / or the transmission control unit 15c , the components of the drive unit 2 can be connected to each other via a CAN bus for data exchange.

The engine control unit 15a is designed to engine intervention by MSE the internal combustion engine 16 to drive and other data with the internal combustion engine 16 assigned sensors are detected, read. Furthermore, the engine control unit 15a adapted to transmission information regarding an engaged gear of the vehicle transmission 6 from the gearbox control unit 15c read. Furthermore, the engine control unit 15a adapted to sensors of the vehicle transmission 6 via the gearbox control unit 15c read. Furthermore, the engine control unit 15a for data exchange with the hybrid control unit 15c and the transmission control unit 15d educated. Finally, the engine control unit 15a for receiving a clutch signal of the clutch 5 formed, in particular information, whether the clutch 5 is open or closed.

In addition, the engine control unit 15a configured to determine a maximum possible engine braking torque MMB and to the ABS / ESP control unit 15b transferred to. For this purpose, in the present embodiment, the engine control unit 15a on models to determine the current braking effects of the respective braking mechanisms. Furthermore, the sum of all potential braking effects, ie the maximum braking effect of the braking torque provided by the engine brake, is also determined.

The engine braking requirement MBA is provided by the ABS / ESP controller 15b always within the framework of the permanent feedback of the engine control unit 15a held over a maximum available engine braking torque. This achieves a vehicle braking behavior optimized over the entire brake system with maximum use or protection of individual components.

The ABS / ESP control unit 15b is adapted to a driver brake request FBW on an actuation of the brake actuator 11 read into. Further, the ABS ESP controller 15b adapted to read in a value for a wheel speed RDZ, that of the friction brake 10 associated wheel speed sensors (not shown) is detected.

In addition, the ABS / ESP control unit 15b configured to determine a desired brake pressure SBD and to the brake pressure actuators 18 wherein the desired brake pressure SBD may be wheel-specific to provide the function of an ABS and ESP system. The brake pressure actuators 18 put on the receipt of the respective target brake pressure SBD out a respective wheel brake pressure RBD for the friction brake 10 ready.

Furthermore, the ABS / ESP control unit 15b for data exchange with the gearbox control unit 15c formed, in turn, for data exchange with the vehicle transmission 6 is formed, and the ABS / ESP control unit 15b is for data exchange with the hybrid control unit 15d formed, in turn, for data exchange with the electric motor 17 is trained.

Finally, the ABS / ESP controller 15b configured to determine an engine brake request MBA and to the engine control unit 15a upon receipt of the engine braking request MBA, transmits an engine drag torque to decelerate the motor vehicle 1 wherein the braking effect of the engine brake is composed of a plurality of individual braking effects E1, E2,..., En based on a plurality of braking mechanisms. In other words, in the present embodiment form the engine control unit 15a and the ABS / ESP controller 15b a device for providing a braking effect in a motor vehicle 1 with a friction brake 10 and with the engine brake for braking the motor vehicle 1 wherein a braking effect of the engine brake is composed of a plurality of individual brake actions E1, E2, ..., En based on a plurality of brake mechanisms.

As the motor vehicle 1 in the present embodiment, also a usable as a regenerative brake hybrid drive with a generator operable electric motor 17 has, has the braking device of the motor vehicle 1 in the present embodiment, three brakes: the friction brake 10 , a regenerative brake and an engine brake. The brakes are for braking the motor vehicle 1 trained and therefore differ from a parking or parking brake of a motor vehicle 1 for holding at a standstill, to prevent accidental startup. Notwithstanding the present embodiment, the brake device can also have only two brakes, so no regenerative braking.

Here, in the present embodiment, the engine control unit 15a designed to associate the individual brake effects E1, E2,..., En with a priority P1, P2,..., Pn, if necessary a selection from the individual brake effects E1, E2,..., En according to the assigned priorities P1, P2, ..., Pn and to activate the engine brake accordingly. The priorities P1, P2, ..., Pn may be a position in a list or a table, or the priorities P1, P2, ..., Pn are numerical values.

When assigning the priorities P1, P2, ..., Pn takes into account the engine control unit 15a For example, the amount of the individual brake effects E1, E2, ..., En, ie their maximum values, and / or the temporal nature of the individual brake effects E1, E2, ..., En, ie their dynamics and thus their temporal availability and / or compensation measures to compensate for side effects of the individual brake effects E1, E2, ..., En are required and / or whether further side or cross-effects by the individual brake effects E1, E2, ..., En occur and / or whether the individual brake effects E1, E2,. .., En can cause damage.

The individual brake effects E1, E2,..., En can be charge-exchange losses. The charge cycle losses may be due to intake side throttling, exhaust side throttling, camshaft timing, such as, e.g. Hub and / or phase, or based on Jake-Brake, which is understood to mean opening of exhaust valves at the end of a compression stroke. In this case, the individual braking effects E1, E2,..., En based on changes in charge exchange can be adapted to the braking requirement by changing parameters.

When the internal combustion engine 16 is a gasoline engine, z. B. a braking effect by a suction-side charge throttling by closing a throttle or a throttle valve and a fuel cut (fuel cut). If, however, the internal combustion engine 16 is a diesel engine, the braking effect by exhaust throttle, ie by increasing a Exhaust counterpressure can be achieved via the corresponding locations of a variable turbine geometry of an exhaust-gas-charged charging device or via a closing of an exhaust gas flap. Optionally, some of the usual in the one engine concept throttle bodies are also present in the other engine concept and there used in the same way.

Another single braking effect E1, E2, ..., En can mechanical consumers 7 based, with the internal combustion engine 16 are coupled, ie driven by him, such as an air compressor. The increased performance of the air conditioning compressor can be compensated by a reduction of the heat exchange with the passenger compartment, ie by a reduction in performance of a blower. It can on mechanical consumers 7 based single braking effects E1, E2, ..., En can be varied by changing parameters.

Further individual brake effects E1, E2,..., En can be based on electrical consumers 7 The motor drag torque due to an increased power demand on a generator-operated electric machine, such as a regenerative electric motor 17 , such as increase to an alternator. Electrical consumers may also be an oil pump, a water pump, a radiator fan, or disc heaters. An increased power of a water pump or a radiator fan can be compensated by a further closing of a thermostat in the coolant circuit, such as an electrothermostat. It can be on electrical consumers 7 based single braking effects E1, E2, ..., En can be varied by changing parameters.

Finally, individual brake effects E1, E2,..., En can also result in internal engine friction losses or mechanical inertia of the rotating masses of the drive unit 2 be. For example, the rotating masses may be a crankshaft of the internal combustion engine 16 but also parts of the vehicle drivetrain 3 act. The individual braking effects based on internal engine friction losses can be varied indirectly by changing parameters such as an engine speed given by a transmission ratio.

In 3 a method is described by means of a flowchart.

The process starts with a step S100. In a further step S200, the engine control unit checks 15a Whether there is an engine brake request MBA.

If there is no engine braking request MBA, the method is continued with a step S300 in which any measures taken to increase the engine drag torque are reset.

If, on the other hand, an engine braking request MBA is present, the method is continued with a step S400, in which it is checked whether an adhesion between the drive unit 2 and the roadway is present, ie, whether the clutch 5 is closed, a gear is engaged and whether the tires are non-positive.

If this is not the case, the method continues with step S300.

Conversely, if there is a positive connection, the method is continued with a step S500.

In step S500, the ABS / ESP controller checks 15b whether the driver's brake request FBW indicates a full or panic braking. For this purpose, the driver's braking request FBW is compared with a threshold value and closed on a full or panic braking when the driver's braking request FBW is greater than the threshold.

If the driver brake request FBW is greater than the threshold value, the process proceeds to a step S600 in which a maximum braking effect of the engine brake is requested.

If, on the other hand, the driver brake request FBW is less than the threshold value, the method continues with a step S700 in which each individual braking effect E1, E2,..., En is assigned a priority P1, P2,..., Pn and the measure for activating the engine brake with the highest priority P1, P2, ..., Pn is selected and implemented.

In a step S800 it is checked whether with the in step 700 introduced measures of the driver brake request FBW has been met or not, ie, whether the driver's brake request FBW corresponding braking effect or delay has been provided or not.

The deceleration will normally be from the individual wheel speed signals of the friction brake 10 certainly.

If no braking effect corresponding to the driver brake request FBW has been provided, the method continues with a step S900, in which the measure for activating the engine brake with the next lowest priority P1, P2,..., Pn is selected and implemented.

If a braking torque corresponding to or exceeding the driver brake request FBW has been provided, the method is continued with a step S1000, in which the activated measure or the activated measures are adjusted, for example by adjusting adjustable parameters.

For this reason, the single measure with the highest priority should be scalable, i. it must be adaptable to a nominal value via variable parameters. This ensures that a brake request is always accurately implemented.

Finally, the process continues with the query in step S200 as to whether there is again an engine braking request MBA.

The method described outlines a new approach of the so-called cooperative braking with the involvement of the engine control. Cyclic current and potential contributions of the available individual motor braking measures or individual braking effects (E1, E2, ..., En) are calculated and their heights transmitted to a higher-level (master) control unit. This is typically an ABS / ESP controller 15b That is an engine braking request MBA in this framework to the engine control unit 15a passes. The latter accurately implements this engine braking requirement MBA.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19604134 A1 [0004]

Claims (15)

Method for providing a braking effect in a motor vehicle (1), in particular in the context of cooperative braking, wherein the motor vehicle (1) has a braking device with a friction brake (10) and with at least one engine brake for braking the motor vehicle (1), wherein a braking effect the engine brake is composed of a plurality of individual braking effects (E1, E2, ..., En) based on a plurality of braking mechanisms, comprising the steps of: Assignment of priorities (P1, P2,..., Pn) to the individual brake effects (E1, E2,..., En) of the engine brake, - Selecting at least one of the individual brake effects (E1, E2, ..., En) according to the assigned priorities (P1, P2, ..., Pn), and Activating the engine brake by converting the selected single braking effect (E1, E2,..., En) to provide the braking effect: Method according to Claim 1 wherein it is detected whether there is a frictional connection between a drive unit (2) of the motor vehicle (1) and a roadway, and activating the engine brake to provide the braking effect only to a detected presence of a frictional connection between the drive unit (2) of the motor vehicle (1 ) and the roadway takes place. Method according to Claim 1 , wherein at least one of the individual brake effects (E1, E2, ..., En) is variable, and in the activation of the engine brake, the at least one individual braking effect (E1, E2, ..., En) is changed. Method according to Claim 1 . 2 or 3 in which the scaling of the values of the individual brake effects (E1, E2,..., En) and / or the magnitude of the individual brake effects (E1, E2,...) is taken into account when assigning the priorities (P1, P2,..., Pn). ., En) and / or the temporal nature of the individual brake effects (E1, E2, ..., En) and / or whether compensatory measures to compensate for side effects of the individual brake effects (E1, E2, ..., En) are required and / or whether further side effects or lateral effects occur due to the individual brake effects (E1, E2, ..., En) and / or whether the individual brake effects (E1, E2, ..., En) cause damage and / or dynamics of the individual brake effects (E1, E2 , ..., En). Method according to one of Claims 1 to 4 wherein a height of a driver brake request (FBW) is determined, and the value is taken into account when assigning the priorities (P1, P2, ..., Pn). Method according to one of Claims 1 to 5 , wherein individual brake effects (E1, E2, ..., En) charge exchange losses of a drive unit (2) of the motor vehicle (1) are assigned and / or associated with a combustion process of an internal combustion engine (16) of the motor vehicle (1) and / or a mechanical load (7) of the motor vehicle (1) are assigned and / or an electrical load (7) of the motor vehicle (1) are assigned and / or friction losses of a drive unit (2) of the motor vehicle (1) are assigned and / or inertia of a drive unit (2 ) of the motor vehicle are assigned. Method according to one of Claims 1 to 6 , wherein from a control unit (15) of the motor vehicle (1), in particular an ABS / ESP control unit (15b) of the control unit (15), a braking request is transmitted to the engine brake within its potential. Method according to one of Claims 1 to 7 in which an engine control unit (15a) assigns the priorities (P1, P2,..., Pn) to the individual brake effects (E1, E2,..., En) of the control unit (15) and at least one of the individual brake effects (E1, E2, ..., En) according to the assigned priorities (P1, P2, ..., Pn) and activates the engine brake by implementing the selected single braking action (E1, E2, ..., En) to provide the braking effect. Method according to one of Claims 1 to 8th wherein an engine control unit (15a) of the control unit (15) determines a level of at least one of the individual brake effects (E1, E2, ..., En). Method according to one of Claims 1 to 9 wherein a mathematical model is used to determine braking effects of the individual braking effects (E1, E2, ..., En) based on the plurality of braking mechanisms. Method according to Claim 10 wherein the model is implemented on a control unit (15) of the motor vehicle (1), in particular an engine control unit (15a) of the control unit (15). Device for providing a braking effect in a motor vehicle (1) having a braking device with a friction brake (10) and with an engine brake for braking the motor vehicle (1), wherein a braking effect of the engine brake consists of a plurality of individual brake effects (E1, E2, .. ., En) based on a plurality of brake mechanisms, wherein the device is configured to - assign priorities (P1, P2, ..., Pn) to the individual brake effects (E1, E2, ..., En), - Select of at least one of the individual brake effects (E1, E2, ..., En) according to the assigned priorities (P1, P2, ..., Pn), and Activating the engine brake to provide the braking effect by translating the selected single braking action (E1, E2, ..., En). Motor vehicle (1) comprising: - a braking device with a friction brake (10) and an engine brake; and - a device according to Claim 12 , A computer program which, when executed in a data processing device, is arranged to perform all the steps of a method according to any one of Claims 1 to 11 perform. Machine-readable storage medium on which a computer program is based Claim 14 is stored.

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