Operate the disconnect clutch for connecting and disconnecting the vehicle's retarder

Abstract

A method for operating a braking system of a vehicle (20) is provided, the braking system having at least one retarder and a disconnecting clutch for coupling and disconnecting the retarder to a power flow of a drive train of the vehicle. The disconnecting clutch is closed as a function of one or more influencing variables. The influencing variable or one of the influencing variables is a predetermined distance (X1) between the vehicle (20) and a location that is smaller than a given condition (22) in the vehicle environment.

Description

Technical Field

[0001] The invention relates to a method for operating a braking system of a vehicle, in particular a motor vehicle. The braking system has at least one retarder and a separating clutch, which is used to connect and disconnect the retarder from the power flow of the vehicle's drive train. In this case, the separating clutch is closed as a function of one or more influencing variables. The invention also relates to a control for correspondingly actuating such a separating clutch. Background Art

[0002] Vehicle brake systems with retarders are known and are often found, in particular, in heavy-duty vehicles. One of the advantages of retarders compared to conventional service brakes, such as disc brakes or drum brakes, is their virtually wear-free operation. Retarders are therefore primarily used to relieve the wear of the service brakes during longer braking operations.

[0003] It is also known to design the retarder so that it can be connected and disconnected from the power flow of the vehicle's drive train by means of a separation clutch. The document SE 201050160 A1 is mentioned only as an example. The advantage is that when the retarder is disconnected by means of the separation clutch, the operating losses of the drive train are particularly low. In this way, the traction losses of the retarder outside its braking operation are minimized.

[0004] In order to enable the reduction gear to play a braking role in the power flow of the drive train, such a separation clutch must first be closed in order to couple the reduction gear to the power flow in the drive train. However, this closure and the subsequent activation of the reduction gear require time. In addition, a certain amount of wear is caused in the separation clutch when closing the separation clutch. In addition, when closing the separation clutch, torque shocks may be introduced into the drive train, which can be perceived by shaking, vibrations or noise.

[0005] DE 10 2013 009 535 A1 discloses a method for controlling a hydraulic retarder in a motor vehicle that can be disconnected by a disconnecting clutch. A drive motor that can be controlled by an actuator is provided. The drive motor is operated in a first operating state (so-called traction operation) and a second operating state (so-called coasting operation) according to the actuation of the actuator. The hydraulic retarder has a driven rotor and a stator. Alternatively, the hydraulic retarder has a driven rotor and a counter-rotor that is driven in the opposite direction. The stator and the rotor / counter-rotor form a working chamber that can be filled with a working medium and can be emptied of the working medium. The rotor can be selectively disconnected from the drive train by means of a disconnecting clutch and can be fixedly connected to the drive train in a rotational sense. Therefore, in a braking operation initiated by the vehicle driver or a driving assistance system, the rotor is driven by means of a closed disconnecting clutch in a manner relative to the stationary stator or in a manner opposite to the counter-rotor. Therefore, when the working chamber is filled, the torque is transmitted from the rotor to the stator or the counter-rotor. In a non-braking operation initiated by the vehicle driver or a driving assistance system, the transmission of drive power to the rotor and / or counter-rotor is interrupted by means of a disconnected disconnect clutch, and the working medium of the working chamber is emptied. During the transition from non-braking operation to braking operation, the disconnect clutch is closed and the working chamber is filled with working medium. During the transition from braking operation to non-braking operation, the working medium of the working chamber is emptied and the disconnect clutch is disconnected simultaneously or with a delay. It is proposed that the topography of the driving section just traveled by the motor vehicle is detected or determined during the coasting operation. In this case, during non-braking operation, the disconnect clutch is closed in a manner dependent on the topography, independent of the initiation of the braking operation by the vehicle driver or the driving assistance system.

[0006] In addition, a method for controlling a separation clutch in a powertrain of a motor vehicle, which has a drive motor and a reducer, is known from DE 10 2017 104 600 A1. The separation clutch is arranged between the drive motor and / or the powertrain and the reducer. Therefore, the rotor of the reducer can be switched to a drive connection with the drive motor and / or the powertrain by means of the separation clutch, and therefore the working chamber of the reducer can be filled with an operating medium to generate braking power. Thus, a braking torque is applied to the powertrain and / or the drive motor by the reducer. A control device is provided here, by means of which the separation clutch can be switched to a closed position or a disconnected position. Switching the separation clutch to the closed position is achieved according to at least one input signal to the control device. Switching the separation clutch back to the disconnected position is achieved according to the fact that there is substantially no working medium in the working chamber of the reducer and at least one other operating parameter and / or environmental parameter is not higher than a preset limit value. Here, it can now be proposed that the separation clutch is switched to the disengaged position only when at least one of the following operating parameters and / or environmental parameters is met and / or does not exceed a determinable limit value: downhill slope of the road, time or distance until the downhill section is reached, generation of a corresponding input signal by the driver, failure to generate a final retarder braking within a defined time interval, exceeding certain limit values ​​of the vehicle's service brakes due to previous braking. Summary of the invention

[0007] The object of the present invention is to improve the prior art.

[0008] This object is achieved by providing a method for operating a brake system of a vehicle. Preferred embodiments thereof can be derived from this description.

[0009] Therefore, a method for operating a braking system of a vehicle, in particular a motor vehicle, is proposed. The braking system has at least one retarder and a separating clutch for coupling and decoupling the retarder to a force flow of a drive train of the vehicle, wherein the force flow can also occur in the drive train as a torque flow or a mechanical power flow.

[0010] The disconnect clutch is (automatically) closed as a function of an influencing variable or a plurality of influencing variables. It is provided that the influencing variable or one of the plurality of influencing variables is less than a predefined distance between the vehicle and a location of a given condition in the vehicle environment. Optionally, the disconnect clutch can then also be (automatically) opened as a function of the influencing variable or the plurality of influencing variables.

[0011] Therefore, within the scope of the proposed method, the distance between the vehicle and a location of a given condition in the vehicle environment is determined. If this distance is less than a specific, predefined value (hereinafter also referred to as a threshold distance), then (if no other influencing variables are mentioned for this) the separation clutch is closed. Thus, in this way, the previously disconnected retarder is connected to the force flow of the drive train, so that the retarder is ready. If there is also a corresponding request for the retarder to perform a braking operation (i.e. a braking request), the retarder can now generate a braking force in the drive train. As a result, the vehicle can be braked with the aid of the retarder. This is not possible when the separation clutch is open, because the retarder is disconnected from the force flow of the drive train.

[0012] In this way, it is possible to close the separation clutch only when an operation of the retarder is about to occur with a high probability, thereby avoiding unnecessary frequent closing of the separation clutch and the disadvantages associated therewith.

[0013] Therefore, preferably, such a closing of the clutch is carried out in anticipation of an urgent request for a braking operation of the retarder. Therefore, when the separation clutch is closed, there is still no braking request for the retarder. Accordingly, it is particularly proposed that after the separation clutch is closed, the retarder is braked only when there is an additional braking request for the retarder. Therefore, the separation clutch is first automatically closed according to the mentioned distance between the vehicle and the location position of the given conditions in the vehicle environment. However, the braking operation of the retarder is only realized due to the additional braking request for the retarder. In this way, appropriate use of the retarder is achieved. The braking request is realized in particular as a corresponding braking signal, in particular as an electric braking signal. The braking request can contain the desired braking effect of the retarder.

[0014] A braking request for a retarder is in particular a request by a vehicle user, in particular a driver of the vehicle, to initiate braking of the retarder. The vehicle user generates the braking request by manual input, for example by means of a joystick or a manual switch or a foot switch or a foot pedal. In this way, the vehicle user also predefines, for example, the desired braking effect to be exerted by the retarder on the vehicle. Such input devices are known per se.

[0015] In other words, it is preferably monitored after the separation clutch is closed whether there is a braking request for the retarder. If this is not yet the case, the retarder has no braking effect. Only when the presence of a braking request is detected is the retarder subsequently put into braking operation. Therefore, only then is the vehicle braked by the retarder. Therefore, there can be a significant time span between the closing of the separation clutch and the actual start of the braking operation of the retarder.

[0016] If no braking request is received, the disconnecting clutch is preferably disconnected again without the retarder initiating a braking operation. This disconnection can be realized as a function of one or more influencing variables, i.e. also as a function of the mentioned distance between the vehicle and a location for given conditions in the vehicle environment. For example, the disconnecting clutch is automatically disconnected again when the vehicle is sufficiently far from the location.

[0017] In addition to the method, a control unit is also provided. The control unit is used to actuate the disconnect clutch, which is used to connect and disconnect the retarder of the vehicle brake system to the force flow of the vehicle drive train. As explained, a braking operation can only be performed when the disconnect clutch is closed and the retarder is therefore connected to the force flow.

[0018] The controller is designed to carry out the proposed method. The controller therefore has in particular a data memory and a corresponding computing device in order to autonomously and exclusively process the mentioned influencing variable or the mentioned influencing variables in the sense of the proposed method and subsequently generate a signal for closing the separating clutch (and optionally also a signal for opening the separating clutch). Preferably, the controller is also designed to implement a braking operation of the retarder based on a braking request.

[0019] As already explained at the outset, a retarder is a virtually wear-free braking device for braking a vehicle. A retarder is thus different from a service brake, which acts due to component friction and therefore has friction. Such a service brake is usually implemented as a disk brake or a drum brake.

[0020] The retarder is designed in particular (but not necessarily) as a hydraulic retarder. The hydraulic retarder has a rotor provided with blades and a stator or a mating rotor acting on the rotor in a known manner. The rotor or the mating rotor also has blades. A working chamber of the retarder is formed between the rotor (on the one hand) and the stator or the mating rotor (on the other hand). The working chamber is filled with a working fluid at least in the braking operation of the retarder. In the braking operation, the rotor moves relative to the stator or the mating rotor, thereby generating a fluid flow. This flow of the working fluid produces a braking effect on the rotor. The rotor can be connected to the powertrain by a separation clutch. Therefore, the retarder can produce a braking effect in the powertrain when the clutch is closed. Outside the braking operation, that is, when the separation clutch is disconnected, the working fluid of the working chamber of the retarder is preferably emptied. Before, after or during the closing of the separation clutch, in order to prepare the retarder, the working chamber is at least partially filled with a working fluid. Subsequently, the setting of the braking power of the retarder can be achieved by setting the distance between the rotor and the stator (or between the rotor and the mating rotor), or by setting the amount of the working fluid located in the working chamber. The braking dynamics of the retarder are set in particular as a function of the braking effect of the retarder desired by means of the braking request.

[0021] The reducer can be arranged at any suitable position of the powertrain. The reducer can be arranged in particular on the input side or output side of the transmission (in particular a multi-stage shift transmission) of the powertrain. However, the reducer can also be integrated into such a transmission, in particular by being arranged in a transmission housing or housing part (e.g. a housing cover) to which it belongs. The control device of the reducer can be separated from the control device of the transmission, or the control device of the reducer can be integrated into the control device of the transmission. The mechanical branch from the powertrain to the reducer can be arranged at a suitable position of the powertrain. The branch is formed in particular by a spur gear transmission or a chain transmission, which is in particular each designed as a high drive stage. The separation clutch can be arranged on the branch itself, or spatially and / or functionally arranged between the branch and the reducer.

[0022] A separation clutch is to be understood as a mechanical device by means of which the input end of the device can be selectively mechanically coupled and disconnected with the output end of the device. Here, in the coupled state, force transmission or torque transmission can be achieved between the input end and the output end, which is almost impossible to achieve in the disconnected state. Preferably, the separation clutch is implemented as a shape-fitting or friction-fitting clutch, such as a claw clutch or a multi-plate clutch. The separation clutch is implemented so that the separation clutch can selectively couple the reducer to the force flow of the power train (clutch closure) and can disconnect the reducer from the force flow of the power train (clutch disconnection). The force flow in this power train is achieved between the drive motor for traveling of the vehicle and the road surface at least during the traction operation of the power train. For this purpose, the drive motor drives the drive wheels or tracks of the vehicle, which are then in driving contact with the road surface. By coupling the reducer to the force flow, the vehicle can therefore be braked by the reducer.

[0023] In order to determine whether and what relevant given conditions exist in the vehicle environment and, if applicable, their corresponding locations, the following items can be used in particular:

[0024] The vehicle's environmental sensing device; and / or

[0025] Car-to-X communication systems of vehicles; this includes car-to-car communication systems and car-to-infrastructure communication systems, whereby two-way communication between the vehicle on the one hand and the traffic infrastructure and / or other traffic participants on the other hand can be achieved in the vehicle's environment; and / or

[0026] Other radio broadcast systems or mobile radio systems, by means of which the vehicle can automatically receive evaluable and current traffic information or other information about relevant given conditions in the vehicle's surroundings; these include, in particular, TMC (Traffic Message Channel) and traffic information systems of map service providers, mobile radio providers or mobile phone providers.

[0027] The vehicle's environment sensor is used to detect the vehicle's immediate environment by the vehicle's sensors. Such an environment sensor can be a sensor system based on radar (RADAR) or light radar (LIDAR) or ultrasound or at least one optical camera, which is arranged on the vehicle.

[0028] The environmental sensor system can also be used to detect the behavior of road users in the vehicle's environment and use this behavior as one of the influencing variables when deciding to close the separation clutch. Thus, for example, the braking behavior and / or acceleration behavior of one or more other road users in front of the vehicle can be taken into account.

[0029] The current distance (actual distance) between the vehicle and the location of the given condition in the vehicle environment can be determined in any manner. For this purpose, in particular, the vehicle's environment sensor system can be used. Thus, the current distance between the vehicle and the location of the given condition can be measured directly with the aid of the environment sensor system (for example, by means of the propagation time method). However, the current distance can also be calculated from the given condition and the current (absolute or relative) location of the vehicle. The basis for this can be the corresponding position information received by the vehicle. The vehicle's own location can be determined, for example, with the aid of the vehicle's navigation system or position determination system.

[0030] The specific value of the preset distance (threshold distance) can be stored in a fixed manner in particular in a controller for operating the separation clutch, or the specific value can be generated dynamically. The specific value is preset in this way. The preset distance can be a time distance or a spatial distance. Here, the time distance is the time span that the vehicle is expected to need to reach the location of the given condition. Here, the spatial distance is the distance between the vehicle and the location of the given condition. This can be a direct distance or a distance along the expected movement path of the vehicle.

[0031] The pre-set distance (threshold distance) can also be the artificial horizon of the vehicle. Here, the artificial horizon is the spatial area around the vehicle, in which the given conditions occurring in the given spatial area are considered to be basically related to the vehicle. And the given conditions occurring outside the artificial horizon and detected by the vehicle are considered to be irrelevant to the vehicle or at least not very relevant. The artificial horizon can be defined, for example, by measuring the spatial area around the vehicle and can be stored in the controller in this way. The artificial horizon can be a pre-set, fully utilized range of action of the environmental sensor device, which is smaller than the technically possible range of action. In this way, the given conditions outside the artificial horizon can be ignored when deciding to close the separation clutch. Therefore, it is possible to prevent the separation clutch from being closed unnecessarily frequently.

[0032] The recognition of "less than a pre-set distance" can be obtained in any suitable manner. However, within the scope of the present invention, the actual distance mentioned between the vehicle and the location of the given condition is preferably compared with the threshold distance mentioned. If the actual distance is greater than the threshold distance, the influencing variable "less than a pre-set distance between the vehicle and the location of the given condition" is not satisfied. Therefore, the probability of immediately activating the retarder is relatively low. Therefore, the separation clutch can then remain disconnected (if the separation clutch was previously disconnected) or be disconnected (if the separation clutch was previously closed). If the actual distance is less than the threshold distance, the influencing variable "less than a pre-set distance between the vehicle and the location of the given condition" is satisfied. Therefore, the probability of immediately activating the retarder is relatively high. Therefore, the separation clutch can then remain closed (if the separation clutch was previously closed) or be closed (if the separation clutch was previously disconnected). This comparison between the actual distance and the threshold distance can be performed in the proposed controller, for example, by means of a suitable mathematical operation, with the help of the corresponding specific values.

[0033] Given conditions in the vehicle environment are objects or events in the vehicle environment that can be assigned a specific location and whose meaning is recognizable for the vehicle. That is, given conditions that cannot be assigned a location or whose meaning is not recognizable for the vehicle are not considered as an influencing variable. However, these given conditions can be taken into account in the form of further influencing variables when deciding on the closing of the retarder.

[0034] In this context, the vehicle environment is understood to be in particular a spatial region around the vehicle that can have an influence on the current operation of the vehicle and on the upcoming operation. In this context, the vehicle environment in front of the vehicle in the direction of travel is particularly taken into account. Thus, a given condition in the vehicle environment can be an event or a physical object or a geographical point or a geographical region with a specific location.

[0035] A given condition in the sense of the proposed method may be one or more or all of the following:

[0036] Speed ​​limits (i.e. the maximum speed permitted); this also includes consideration of changes in speed limits;

[0037] Downhill or uphill; this also includes taking into account more detailed information about the downhill or uphill, such as its slope, or the change in slope during the downhill or uphill journey;

[0038] Curves; this also includes taking into account more detailed information about the curve, such as its radius or how the radius changes during the turn;

[0039] · a residential area, especially a residential area or village area;

[0040] Construction area;

[0041] Dangerous areas;

[0042] The type of road, e.g. motorway, country road, state highway, farm track, race track, or a change in road type;

[0043] Traffic jams or traffic stagnation or slow traffic;

[0044] A vehicle driving ahead, especially another vehicle driving ahead directly in front of the vehicle;

[0045] · Intersections or roundabouts;

[0046] Technical devices for traffic control or access restriction, such as, in particular, indicator lights (signal lights) or barrier systems or lifting bollards;

[0047] ·pedestrian crossing;

[0048] ·railroad crossing.

[0049] In addition to the given conditions mentioned, there may be a plurality of other given conditions (not explicitly mentioned here) which may each be considered as an influencing variable when closing the separating clutch and optionally also when opening the separating clutch. Information about these given conditions may be obtained by means of an environmental sensor system and / or a vehicle-to-X communication system and / or other radio broadcast systems or mobile radio systems.

[0050] It can be provided that the separation clutch is already closed when the predetermined distance between the vehicle and the location of only one of the plurality of given conditions in the vehicle environment is less than 0. Alternatively, it can be provided that one or more further influencing variables are even considered in order to close the separation clutch.

[0051] In particular, at least one further (negative) influencing variable is provided, which (if present) substantially prevents the clutch from closing. For this purpose, these influencing variables can be given a correspondingly high priority. Such an influencing variable can be an excessive temperature of the retarder or the operating fluid of the retarder or the disconnecting clutch. Such an influencing variable can be the wear state of the retarder or the operating fluid of the retarder or the disconnecting clutch. Such an influencing variable can be a detected defect of the disconnecting clutch or the retarder. Such an influencing variable can be the currently existing operation or the immediately preceding operation of a control device of the vehicle, which is used to prevent the vehicle from sliding out (also called driving dynamics control device or electronic stability control device, Electronic Stability Control), or to prevent the drive wheel from slipping (also called traction control device or drive slip control device), or to prevent the wheel from locking (also called anti-lock braking system or automatic anti-lock braking device). It can also be provided that in the presence of one or more such (negative) influencing variables, the closed disconnecting clutch is immediately completely or partially opened. In this way, an impermissible operation of the retarder and / or the disconnecting clutch can be reliably prohibited.

[0052] Preferably, the separation clutch is closed only when the given conditions in the vehicle environment are expected to require a change in the current speed (actual speed) of the vehicle. For example, if the given condition is a speed limit ahead and the actual speed of the vehicle is already lower than the maximum speed allowed there, then there is no need to close the separation clutch. The corresponding content applies to the situation where the given condition is a slow-traffic area ahead and the actual speed of the vehicle is already lower than the speed that dominates there. In these cases, the braking operation of the retarder is relatively impossible. Therefore, a determined, belonging theoretical speed is preferably assigned to these given conditions in the vehicle environment. Therefore, the theoretical speed is a feature of the corresponding given conditions. It is not necessary that the given condition itself has this theoretical speed in the form of an inherent speed. The theoretical speed can be assigned according to the category for the given condition. The given conditions in the vehicle environment are assigned to these categories. Therefore, in particular, different given conditions and / or different categories of given conditions are assigned corresponding, different theoretical speeds. Under some given conditions, the corresponding belonging theoretical speed can also be directly derived from the given condition itself. Therefore, in particular, the maximum speed that dominates there and is allowed is regarded as the belonging theoretical speed in the given condition "speed limit". The corresponding content can be applied to residential areas, construction areas, etc. However, the theoretical speed can also be variable. Therefore, depending on the state of a given condition, a correspondingly belonging, state-dependent theoretical speed can be assigned to the given condition. Therefore, a further influencing variable for closing the clutch can be a speed difference between the actual speed of the vehicle and the theoretical speed for the corresponding given condition. This can prevent the clutch from closing too often without reason.

[0053] Preferably, at least one further influencing variable among the influencing variables is the state of the given condition. Thus, in this way, not only the distance between the vehicle and the given condition is taken into account, but also the state of the given condition. This is particularly meaningful in given conditions, which require or do not require braking of the vehicle depending on the state. This can further prevent the disconnect clutch from being closed more often than necessary.

[0054] The mentioned state of the given condition can be the switching state of the given condition. In other words, when a switchable given condition occurs in the vehicle environment, the current switching state of this given condition is considered as a further influencing variable for closing the separation clutch. The given condition with a switchable state is in particular a light facility (e.g. a traffic light) or a guardrail facility or a lifting column or other switchable device for traffic management or closure. For example, only when the light facility or the guardrail facility requires a stop, it is necessary and possible to brake the retarder in front of the light facility and the guardrail facility and thus close the separation clutch. The switching state of the given condition in the vehicle environment can be determined in different ways according to the given condition, for example by means of an environmental sensor device or a car-to-X communication system or other radio broadcasting system or mobile radio system. In this way, the state information transmitted by the car-to-X communication system from the intelligent light facility or from the intelligent traffic sign can also be considered as an influencing variable. Therefore, it is further possible to prevent the separation clutch from being closed frequently and unnecessarily.

[0055] The state of a given condition can be the state of motion of the given condition. This requires that the given condition itself has a certain speed and / or acceleration. The direction of motion of the given condition can also be considered here. In other words, when a given condition of motion occurs in the vehicle environment, the speed and / or acceleration and / or direction of motion of this given condition are considered as other influencing variables for closing the separation clutch. In particular, instead of the inherent speed and / or inherent acceleration of the given condition, the relative speed and / or relative acceleration between the vehicle and the given condition are involved here. Therefore, if the given condition is another vehicle traveling in front, then when deciding to close the separation clutch, in addition to the distance from the vehicle traveling in front, the speed and / or acceleration of the vehicle traveling in front are also considered. If, for example, the speed of the vehicle traveling in front is greater than the speed of the own vehicle, then even if it is less than the pre-set distance between the two vehicles, it is not necessary to close the separation clutch. That is to say, in this case, the braking operation of the reducer is relatively impossible. If the direction of motion of the given condition is also considered in addition, the decision about closing the separation clutch can be better adapted to cross-travel. Here, the movement state of the given condition can also be determined in different ways depending on the given condition, for example by means of an environmental sensor system or a car-to-X communication system or other radio broadcast systems or mobile radio systems.

[0056] Preferably, the separation clutch is closed as a function of a plurality of influencing variables. In particular, a logic circuit is provided here, which determines the probability of the retarder being activated as a function of the plurality of influencing variables. The separation clutch is then closed as a function of this probability. This logic circuit is in particular part of the proposed controller. A certain intelligence is thus provided for determining this probability (for example in the form of a probability value). If this value is above or below a threshold value, the separation clutch is correspondingly actuated in the sense of closing or opening.

[0057] In principle, it can be provided that when using a plurality of influencing variables, at least some of these influencing variables have different degrees of influence on the decision to close the separator clutch. This is preferably achieved by assigning different priorities to the influencing variables.

[0058] Similar to closing the clutch, the closed separation clutch can be opened according to the influencing variable or at least one of the influencing variables. Therefore, if the predefined distance between the vehicle and the given condition is no longer less than, the separation clutch can be opened accordingly.

[0059] In the manner described, one or more influencing variables can be used to determine the probability or necessity of retarder operation and to deduce therefrom that the separation clutch is closed and opened in an expected manner. The logic circuit presented in the controller can evaluate a single signal or combine different signals in order to generate instructions for operating the separation clutch in the sense of the proposed method. This logic circuit does not have to be implemented in the retarder controller. For this purpose, the vehicle's vehicle master computer, brake controller or other suitable controllers can also be used, which can detect the required signals and can operate the separation clutch. It can be proposed that the proposed method is performed independently of whether the vehicle's drive motor is in a coasting operation or a traction operation.

[0060] It can be provided that a superior brake management device is continuously informed whether the retarder is connected to the force flow of the drive train via the separating clutch and is therefore directly ready for braking (i.e. whether the clutch is closed). As long as the retarder is connected in this sense and is therefore ready for braking, the superior brake management device can always make a request to the retarder. The superior brake management device can also cancel the braking request even if the retarder is disconnected, but this is then only carried out with a delay, because the separating clutch must still be closed first. Accordingly, within the scope of the proposed method, at least one further influencing variable can be a request for immediate closing of the separating clutch. This enables the separating clutch to be closed immediately. Therefore, this further influencing variable is given a correspondingly high priority. However, one or more further influencing variables can also be provided here to prevent such closing, as already explained above.

[0061] In some cases, it may happen that the given condition is only detected when it is already located closer to the vehicle than a predefined distance between the vehicle and the location of the given condition. This may be the case, for example, when a traffic sign is partially obscured or is only detected relatively late by the vehicle with the aid of its surroundings sensor system. In this case, the influencing variable is therefore satisfied immediately upon detection of the given condition. Subsequently, the separation clutch can be closed without further delay, if no further influencing variables are mentioned for this purpose. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The present invention is described in detail below with the aid of the accompanying drawings, from which other preferred embodiments of the present invention can be derived.

[0063] Figure 1 A vehicle powertrain having a couplable and decouplable speed reducer is shown,

[0064] Figure 2 A controller is shown for operating a disconnect clutch for a couplable and decouplable speed reducer.

[0065] Figure 3 A first application scenario of a vehicle having a couplable and decouplable reducer is shown,

[0066] Figure 4 A second application scenario of a vehicle having a couplable and decouplable reducer is shown,

[0067] Figure 5 A third application scenario of a vehicle having a couplable and decouplable reducer is shown,

[0068] Figure 6 A fourth application scenario of a vehicle having a couplable and decouplable reducer is shown,

[0069] Figure 7 A fifth application scenario of a vehicle having a couplable and decouplable reducer is shown,

[0070] Figure 8 A sixth application scenario of a vehicle having a couplable and decouplable retarder is shown. DETAILED DESCRIPTION

[0071] In the figures, identical or at least functionally identical parts, components and units are provided with the same reference symbols.

[0072] Figure 1The power train of a vehicle (especially a motor vehicle, especially a truck or a passenger car) is shown in a top view. The power train has a drive motor 1 for moving the vehicle, and the power train has a transmission 2 for converting the torque of the drive motor 1. Here, the transmission is especially a multi-stage shift transmission. Therefore, the transmission can also be an automated shift transmission or an automatic transmission. In the power train, a drive axle 3 is arranged on the driven side of the transmission 2. The drive axle is connected to the drive wheel 4. Therefore, the driving force (and therefore the corresponding driving torque and the corresponding driving power) can be mechanically transmitted from the drive motor 1 to the drive wheel 4 by means of the power train. The drive wheel 4 is supported on the surface of the roadway. Therefore, in the traction operation of the vehicle, the vehicle can be driven by the drive motor 1.

[0073] The vehicle's service brake in the form of a disk actuator or drum brake 5 is arranged in the region of the drive wheel 4. The service brake 5 is used in particular for short-term braking. The service brake 5 has friction due to its design.

[0074] A speed reducer 6 is also provided in the vehicle as a continuous brake. For example, the speed reducer is a hydraulic speed reducer 6. Therefore, the speed reducer 6 has a rotor 6A on which blades are arranged, and a stator 6B fixed to the housing, on which blades are also arranged. Instead of the stator 6B fixed to the housing, a matching rotor can also be provided, which always rotates in the opposite direction to the rotor 6A when the rotor 6A rotates. However, this does not change the working method of the speed reducer 6 described below.

[0075] A working chamber of the reducer 6 is generated between the rotor 6A and the stator 6B. The working chamber can be filled with a working fluid. When the working chamber is fully filled with the working fluid and relative rotation occurs between the rotor 6A and the stator 6B, the reducer 6 generates a braking torque on the reducer shaft 6C connected to the rotor 6A. The braking torque may depend on the filling degree of the working chamber with the working fluid, and the braking torque may depend on the distance from the rotor 6A and the stator 6B. In the reducer 6, both or one of the two may be designed to be settable.

[0076] The reducer 6 is exemplarily arranged in the region of one end of the driven side of the transmission 2. Alternatively, the reducer can also be connected to the powertrain at other suitable positions. A separation clutch 7 is provided between the powertrain and the reducer 6. The clutch 7 can be disconnected and closed in a targeted and selective manner. According to the embodiment of the clutch 7, the clutch can also be set to an intermediate position, that is, it is allowed to be disconnected and closed only partially. Therefore, by means of the clutch 7, the reducer 6 can be selectively mechanically coupled and disconnected with the power flow of the powertrain. When the reducer 6 is coupled (the clutch 7 is closed), the reducer 6 can produce a braking effect on the vehicle. When the reducer 6 is disconnected (the clutch 7 is disconnected), the reducer 6 is mechanically separated from the power flow of the powertrain. As a result, the reducer cannot produce a braking effect on the vehicle.

[0077] It should be noted here that the retarder 6 still does not produce a braking effect in the coupled state. This is only the case if the filling level of the retarder 6 is additionally set for a braking operation and / or the distance between the rotor 6A and the stator 6B is set for a braking operation. However, the retarder 6 always produces certain traction losses in the coupled state. By disengaging the separation clutch 7, these traction losses can be almost minimized.

[0078] However, the process of closing the disconnect clutch 7 and setting the braking operation at the retarder 6 itself requires time. Therefore, a noticeable time span may pass between the request for a braking operation and the actual onset of the braking effect of the retarder 6. In addition, each closing of the clutch 7 causes wear in the clutch 7 and causes torque shocks that may be audible or perceptible to be introduced into the drive train. It is therefore worthwhile to operate the clutch 7 as intelligently as possible in view of these challenges.

[0079] A controller 8 is provided for actuating the clutch 7. In particular, the controller is also used to actuate the reducer 6 itself, i.e., to set the filling level of the reducer 6 and / or the distance between the rotor 6A and the stator 6B. Information and commands can be supplied to the controller 8. For this purpose, the controller 8 is implemented for actuating the clutch 7. For this purpose, the controller 8 processes the received information and commands with the aid of a logic circuit and outputs corresponding commands to the clutch 7. The actuator assigned to the clutch 7 then implements the commands for the clutch 7. The corresponding contents apply to the reducer 6. The commands of the controller 8 for the reducer are implemented with the aid of the actuator assigned to the reducer 6.

[0080] The retarder 6 and the service brake 5 can be part of a common brake system. However, the retarder 6 can also be embodied as a separate brake system.

[0081] Figure 2A controller 8 is shown. The controller 8 is used to automatically operate a disconnect clutch 7, which is used to connect and disconnect a retarder of a vehicle's braking system from the power flow of the vehicle's drive train. Optionally, the controller 8 is also used to operate the retarder itself. Thus, the braking power of the retarder can be set by means of the controller 8. Figure 2 The controller 8 shown in FIG. 8 is particularly from Figure 1 A controller for actuating the clutch 7 located there.

[0082] The controller 8 is supplied with information and commands on the input side by a plurality of systems of the vehicle. This includes, for example, a brake management device 9. The brake management device 9 is designed in particular to set the vehicle deceleration desired by the vehicle user (in particular the driver) by means of the retarder and / or service brake 5 of the vehicle. The brake management device 9 outputs corresponding commands (signals A) to the controller 8.

[0083] The controller 8 is designed to output information about the state of the disconnect clutch 7 (signal B) to the brake management device 9. The brake management device 9 can thus for example know that the clutch 7 is closed and can therefore set a braking operation via the retarder.

[0084] In addition, the controller 8 is provided with information from the camera system 10 (signal C), information from the adaptive cruise control device 11 (signal D), information from the navigation system 12 (signal E), and information from the vehicle-to-X communication system 13 (signal F) on the input side. As required, other information sources of the controller 8 can be used instead of or in addition to this. The camera system 10 can be part of a surroundings sensor system arranged on the vehicle.

[0085] The control unit 8 can have a device for determining the actual temperature of the operating fluid of the retarder. This information can also be taken into account when deciding to close the separator clutch 7 (signal G).

[0086] The information and commands (signals A to G) are processed by the control unit 8 as various influencing variables when deciding to close and open the clutch. The control unit 8 outputs a corresponding command (signal H) to the separation clutch 7. This command is implemented by the clutch actuator assigned to the separation clutch 7 in that the clutch 7 is actuated accordingly in the sense of closing or opening. In this way, the clutch 7 is thus operated intelligently to a certain extent. When the clutch 7 is closed, the braking operation of the retarder 6 can be set, so that the requested braking effect is set in the vehicle.

[0087] Here, the distance between the vehicle and the location of the given condition in the vehicle environment constitutes an influencing variable generated by the controller 8 based on the received information. If the current distance (actual distance) is less than the pre-set distance (threshold distance), the retarder is likely to be put into operation immediately. Accordingly, the controller 8 can then request that the clutch 7 be closed.

[0088] However, a predefined reason, i.e. a corresponding (negative) influencing variable, may oppose the actuation of the disconnecting clutch 7. For example, the temperature of the working fluid of the retarder (signal G) may be too high, i.e. above a temperature threshold. This other influencing variable may be given a higher priority. Therefore, in order to protect the retarder 6, the controller 8 may determine that the retarder is not allowed to operate and therefore the disconnecting clutch 7 should be kept disconnected or disconnected for safety reasons.

[0089] The following figures each illustrate an application scenario of a vehicle having a reducer that can be coupled and disconnected by a separation clutch. In particular, the vehicle has a Figure 1 The power transmission system, the reducer 6 and the separation clutch 7 and the controller 8. In particular, by means of Figure 2 The controller 8 shown in FIG. 1 is used to operate the separation clutch to connect and disconnect the reducer. Therefore, by means of the separation clutch, the reducer can be selectively connected and disconnected with the power flow of the power transmission system of the vehicle.

[0090] Figure 3 In the upper part, a vehicle 20 equipped with a reduction gear is shown, wherein, as already explained, the reduction gear can be selectively coupled and decoupled with the power flow of the drive train of the vehicle 20 by means of a separation clutch. The vehicle 20 approaches another vehicle 22 located on the same lane 21 at a fixed speed. The other vehicle 22 can also be running at a fixed speed or stopped. The vehicle 22 can be the end of a traffic jam. Therefore, the vehicle 22 or the traffic jam is presented as a given condition in the environment of the vehicle. A location position is assigned to this given condition. This is in particular the current position of the vehicle 22.

[0091] exist Figure 3 In the lower part, two curves are drawn one above the other. The upper curve shows the state of the decoupling clutch for the retarder depending on the road section traveled by the vehicle 20 on the roadway 21. The lower curve shows the braking operation of the retarder depending on the road section traveled by the vehicle 20 on the roadway 21.

[0092] The vehicle 20 has a device for detecting a given condition in the environment of the vehicle, such as in particular a vehicle 22. For this purpose, the vehicle's environmental sensor system is used in particular. For this purpose, a vehicle-to-X communication system and / or other radio broadcast systems or mobile radio systems can also be provided. In addition, the vehicle 20 is also designed to classify the given conditions detected in the environment of the vehicle 20. Thus, the vehicle 20 recognizes the vehicle 22 located ahead on the same lane or recognizes the traffic jam itself. The vehicle 20 can also be designed to determine the current distance (actual distance) to the location of this given condition.

[0093] The controller assigned to the disconnect clutch is designed to generate a command (signal) for operating the disconnect clutch as a function of one or more influencing variables. This command is implemented by the disconnect clutch, i.e. the clutch is then opened or closed. One of the main influencing variables is a pre-set distance X1 (threshold distance) between the vehicle 20 and a location position that is less than a given condition in the vehicle environment. That is, in this case, the probability that the retarder is about to perform a braking operation is high. Figure 3 In the example shown in , the location position of the given condition is the position of the vehicle 22 located in front.

[0094] The vehicle 20 therefore monitors the actual distance to the vehicle 22 in front and compares it with the mentioned threshold distance X1. If the vehicle 20 has approached the vehicle 22 in front, this influencing factor is met.

[0095] Therefore, in the scenario shown, when the distance X1 is less than, the controller immediately generates a command to the separation clutch for closing, which is correspondingly implemented by the actuator of the separation clutch. Figure 3 The lightning symbol at the distance X1 at the upper curve in FIG. 1 shows that the clutch changes from the disconnected state "0" to the closed state "1".

[0096] However, at this point in time, a braking operation of the retarder has not yet been requested. This braking operation is only implemented at the distance X2 between the two vehicles 20, 22, in particular in that the driver of the vehicle 20 additionally triggers a braking request for the retarder. For example, the driver manipulates a handle at the distance X2, with the aid of which the driver sets the braking effect of the retarder. Correspondingly, an instruction for setting the braking operation is generated at the distance X2 and output to the retarder. This instruction is correspondingly implemented by the actuator of the retarder, and the vehicle is then braked accordingly with the aid of the retarder. This process is performed by the actuator of the retarder. Figure 3The lightning symbol at the distance X2 at the lower curve in FIG. Here, the retarder changes from the unbraked state "0" (no brake operation) to the braked state "1" (brake operation). In this way, the vehicle 20 can be braked in time with the help of the retarder before reaching the vehicle 22.

[0097] Another influencing variable when deciding to close the separating clutch may be the relative speed between vehicles 20, 22. If, for example, the preceding vehicle 22 is actually faster than vehicle 20, closing the separating clutch may be omitted even if the threshold distance X1 is currently less than the preceding vehicle 22.

[0098] A further influencing variable when deciding to close the disconnect clutch for the retarder may be the relative acceleration existing between the vehicles 20, 22. If, for example, it is foreseeable that due to the relative acceleration of the vehicles 20, 22 the distance between them will become sufficiently large within a foreseeable time, then closing the disconnect clutch may also be omitted even if the threshold distance X1 is currently less than the distance.

[0099] The process described with respect to vehicle 22 can be carried out for any arbitrary, further given conditions (which are located in the environment of vehicle 20 and which can lead to a possible braking operation of the retarder).

[0100] Figure 4 (and Figure 3 Similarly) in the upper part, a vehicle 20 is shown which is equipped with a reduction gear, wherein the reduction gear can be selectively coupled and decoupled with the power flow of the power train of the vehicle 20 by means of a separation clutch. Figure 3 The vehicle 20 and the method flow are also applicable to Figure 4 .

[0101] The lane 21 on which the vehicle 20 moves is assigned to a certain road type. Now, the vehicle 20 approaches the change of the road type at its inherent speed. For example, it is planned that the vehicle 20 leaves the expressway 23 at the exit and changes to the rural road 24. Or the expressway 23 where the vehicle 20 is located ends and continues to be paved as a national highway 24. With this change of road type, the change of the lane state is usually accompanied. In addition, it is usually accompanied by a change in the maximum speed allowed. This is why the retarder is requested to perform a braking operation with a higher probability before the road type changes.

[0102] If the vehicle 20 is sufficiently close to the change in road type, then this change is in the vehicle's surroundings. This can be achieved, for example, when the change is within the range of action of the vehicle's surrounding sensor system. Such a range is Figure 420 is shown as an arrow in the example. Thus, the change of road types is shown as a given condition in the environment of the vehicle. A location position is assigned to this given condition. This is in particular the geographical location of the change of two road types. The location position of the change can be shown, for example, by local road signs and can therefore be recognized by the vehicle's environmental sensor system. Alternatively, the location position can be stored in a database to which the vehicle 20 can access. The vehicle 20 can determine its own location position, for example, by means of a positioning system.

[0103] If already targeted Figure 3 As explained, the vehicle 20 is designed to detect given conditions in the environment of the vehicle 20 and to classify these given conditions. Therefore, the vehicle 20 also recognizes a change in road type as a given condition, which may require a braking operation of the retarder. Therefore, the vehicle 20 determines whether it is less than a predefined distance X1 from the location of the given condition (here, the change in road type). If this is the case, the corresponding influencing variable for closing the decoupling clutch of the retarder is satisfied. According to Figure 4 , then close the separation clutch, see Figure 4 The lightning symbol at the upper curve in the lower part of . Subsequently, the retarder is ready. Now, the vehicle 20 approaches the change of road type further. At a smaller distance X2 between the vehicle 20 and the change of road type, the retarder is actually requested to perform a braking operation. The retarder is correspondingly activated and the retarder brakes the vehicle 20 accordingly, see Figure 4 The lightning symbol below the curved line in the lower part of the .

[0104] Figure 5 (and Figure 3 and Figure 4 Similarly) in the upper part, a vehicle 20 is shown which is equipped with a reduction gear, wherein the reduction gear can be selectively coupled and decoupled with the power flow of the power train of the vehicle 20 by means of a separation clutch. Figure 3 and Figure 4 The vehicle 20 and the method flow are also applicable to Figure 5 .

[0105] In accordance with Figure 5 In the scenario, there is a downhill slope 25 in front of the vehicle 20 in the direction of travel, but no other vehicles or a change in the type of road. The location of the start of the downhill slope 25 can be determined in the manner described. This is a given condition in the environment of the vehicle 20 when it is sufficiently close to the downhill slope 25. The start of the downhill slope 25 is determined in particular by the fact that a certain slope of the roadway 21 is present or greater therefrom, which could lead to a braking operation of the retarder. The same can apply to the uphill slope of the roadway 21. Figure 3 and Figure 4 Similarly, in Figure 5 In the example, the vehicle 20 thus determines whether the vehicle 20 is less than a predefined distance X1 from the location of the given condition, here the start of the downhill slope 25. As soon as this is the case and no other influencing variables are contrary to this, the separation clutch for the retarder is closed. The retarder is thus ready for a braking operation.

[0106] However, with Figure 3 and Figure 4 In different scenarios, Figure 5 In the example, the decelerator is requested to perform a braking operation only after passing the location position of the given condition (the start of the downhill slope 25). The braking operation is obviously not required at an earlier time point. Therefore, the position of the vehicle 20 requesting the braking operation is located at a distance X2 after the start of the downhill slope 25 in the driving direction.

[0107] Figure 6 and Figure 7 It shows that they can be Figure 3 and Figure 4 Comparative scenes each with the same vehicle 20. Figure 6 The speed limit 26 appears as a given condition in the environment of the vehicle 20. Figure 7 In the example, a curve 27 occurs in the lane 21 of the vehicle 20. In both cases, it is determined whether the position of the vehicle 20 is smaller than the position corresponding to the given conditions (i.e., Figure 6 The start of the speed limit 26 and at Figure 7 The decelerator is thus ready for a braking operation. Figure 6 In the case of the vehicle passing the speed limit 26, the retarder is immediately requested to perform a braking operation. Figure 7 In the example, the retarder is requested to perform a braking operation at a distance X2 before the start of the curve 27.

[0108] The location of speed limit 26 and / or the location of the start of curve 27 can also be determined in the manner described. The start of curve 27 is determined in particular by the fact that a certain curve radius is present or smaller than a certain curve radius which could cause a braking operation of the retarder.

[0109] exist Figure 6In the embodiment of the present invention, a certain theoretical speed is assigned to the speed limit 26 as a given condition as a feature. This theoretical speed should be reached as far as possible when the speed limit 26 is reached. Therefore, the disconnect clutch can only be closed if the actual speed of the vehicle 20 is greater than this theoretical speed. Therefore, a further influencing variable when deciding to close the disconnect clutch can be the speed difference between the actual speed of the vehicle 20 and the theoretical speed assigned to the given condition.

[0110] Figure 8 Shown is a Figures 3 to 7 21 , wherein the given condition in the environment of the vehicle 20 is a geographical area 28. This area 28 can be a residential area, such as a residential area or a village area. Alternatively, the area can be a construction area on the roadway 21. Alternatively, the area can be any other dangerous area on the roadway 21.

[0111] In the entire area 28, the retarder can be braked. The area 28 has a start and an end for the vehicle 20. A dedicated location is assigned to each of the start and the end. Therefore, it is first determined whether the distance X1 from the location of the given condition "start of area 28" is less than a predetermined distance. As soon as this is the case and there are no other influencing variables to the contrary, the separation clutch for the retarder is closed. The retarder is thus ready for a braking operation.

[0112] After passing through the area, it is determined whether the predetermined distance X3 from the location of the given condition "end of area 28" is greater than that. As soon as this is the case and no other influencing variables are contrary to this, the separation clutch for the retarder is disengaged. Thus, although the retarder is no longer ready for a braking operation, this is not necessary because the vehicle 20 is already far enough away from the area 28.

[0113] exist Figure 8 In the case of multiple requests for retarder braking in area 28, this can be Figure 8 In the lower part of the curve below, the retarder changes from the unbraked state "0" (no brake operation) to the braked state "1" (brake operation).

[0114] If other given conditions enter the environment of the vehicle 20, corresponding processing methods can be provided. This can be one, several or all of the following items in particular:

[0115] · intersections or roundabouts,

[0116] Technical devices for traffic control or access restriction, in particular signal lights or barriers or lifting bollards,

[0117] ·pedestrian crossing,

[0118] ·railroad crossing.

[0119] If other given conditions (not explicitly mentioned here) occur in the environment of vehicle 20 , actions may be taken accordingly.

[0120] It is possible that the state of the given condition is variable and the probability of the retarder braking operation depends primarily on this state. This is particularly the case in the above-mentioned technical devices for traffic management or access restriction. In this case, a further influencing variable for closing the separation clutch can be the state of the corresponding given condition. For example, if the vehicle moves towards an open guardrail, the separation clutch can be prevented from closing.

[0121] In the illustrated scenario, after the separation clutch is closed, a braking operation of the retarder is preferably triggered by a vehicle user (especially the driver) of the corresponding vehicle 20. For example, the driver operates a special handle or switch for this purpose. Such input devices are known per se. In this way, a braking request is triggered, which realizes a braking operation of the retarder after the separation clutch is closed. Therefore, after the separation clutch is closed, it is preferably monitored by the controller 8 whether such a (manual) braking request by the vehicle user exists. If this is the case, the controller 8 realizes a corresponding braking operation of the retarder.

[0122] List of Reference Numerals

[0123] 1 Drive motor

[0124] 2 Transmission

[0125] 3 Drive axle

[0126] 4 Drive wheels

[0127] 5 Service brakes

[0128] 6 Reducer

[0129] 6A Rotor

[0130] 6B Stator

[0131] 6C reducer shaft

[0132] 7 Disengagement clutch

[0133] 8 Controller

[0134] 9 Brake Management System

[0135] 10 Camera System

[0136] 11 Speed ​​​​regulating device

[0137] 12 Navigation System

[0138] 13 Car-to-X Communication System

[0139] 20 Vehicles

[0140] 21 Lane

[0141] 22 Given the conditions, vehicle

[0142] 23, 24 Given conditions, road type

[0143] 25 Given conditions, downhill

[0144] 26 Given conditions, speed limit

[0145] 27 Given the conditions, the curve

[0146] 28 Given conditions, geographical area

[0147] A...H signal

[0148] X1 Preset distance

[0149] X2 Request braking distance

[0150] X3 Pre-set distance

Claims

1. A method for operating a braking system of a vehicle (20), the braking system having at least one retarder (6) and a separating clutch (7), the separating clutch being used to couple and disconnect the retarder (6) with the power flow of a drive train of the vehicle, wherein the separating clutch (7) is closed as a function of one or more influencing variables, It is characterized in that The influencing variable or one of the influencing variables is less than a predetermined distance (X1) between the vehicle (20) and a location of a given condition (22, 23, 24, 25, 26, 27, 28) in the vehicle environment, wherein after the separation clutch (7) is closed, it is monitored whether there is a braking request for the retarder (6), If the braking request is present, the retarder (6) is then placed in braking operation. 2 . The method according to claim 1 , wherein the predetermined distance ( X1 ) is a time distance or a space distance.

3. The method according to claim 1, wherein the predetermined distance (X1) is an artificial field of view of the vehicle.

4. The method according to claim 1, wherein the given condition (22, 23, 24, 25, 26, 27, 28) is one or more or all of the following: Speed ​​limit (26), Downhill (25) or uphill, Bend (27), Residential area, Construction area, Dangerous areas, a road type (23, 24) or a change in said road type, Traffic jams or traffic stagnation or slow traffic, The vehicle ahead (22), intersections or roundabouts, Technical devices for traffic management or access restriction, Pedestrian crossings, and railroad crossing. The method according to claim 1 , wherein a further one of the influencing variables is the state of the given condition.

6. The method according to claim 5, wherein: If the given condition is a technical device for traffic management or entry restriction, the state is a switch state of the given condition.

7. The method according to claim 5, wherein: When the given condition is a vehicle (22) traveling ahead, the state is a motion state of the given condition at a speed and / or acceleration of the given condition.

8. The method according to claim 1, wherein the separating clutch (7) is closed as a function of the plurality of influencing variables, The logic circuit determines the probability that the retarder (6) will be activated based on the plurality of influencing variables and closes the separator clutch (7) as a function of the probability.

9. The method as claimed in claim 1, wherein at least one other of the influencing variables is a request for immediate closing of the separator clutch (7).

10. The method according to claim 1, wherein the separator clutch (7) is opened as a function of the influencing variable or at least one of the plurality of influencing variables.

11. The method according to claim 4, wherein the residential area is a residential area or a village area.

12. The method according to claim 4, wherein the road type (23, 24) is a motorway (23), a country road (24), a national highway, a farm track or a race track.

13. The method according to claim 4, wherein the preceding vehicle (22) is another preceding vehicle directly in front of the vehicle.

14. The method according to claim 4, wherein the technical device for traffic management or entry restriction is a signal light facility or a barrier facility or a lifting column.

15. A controller (8) for operating a disconnect clutch (7) for connecting and disconnecting a retarder (6) of a braking system of a vehicle (20) with a power transmission system of the vehicle (20), It is characterized in that The controller (8) is designed to carry out the method according to any of the preceding claims.

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