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

Abstract

A possibility for operating a braking system of a vehicle (9) is provided, the braking system having at least one retarder (6) and a separating clutch (7) for coupling and disconnecting the retarder (6) with the power flow of a drive train (1, 2, 3, 4) of the vehicle. In this case, a driving situation of the vehicle (9) that is present at a user request (R) for a braking operation (R*) of the retarder (6) is learned or has been learned. When a driving situation that corresponds to the learned driving situation subsequently occurs, the separating clutch (7) is closed.

Description

Technical Field

[0001] The invention relates to a method for operating a braking system of a vehicle. The braking system has at least one retarder and a disconnecting clutch. The disconnecting clutch is used to connect and disconnect the retarder to the power flow of the vehicle's drive train. The invention also relates to a control unit and a computer program product for correspondingly actuating the disconnecting 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 selectively coupled and decoupled 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 decoupled 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 force flow of such a power train, the separation clutch must first be closed in order to couple the reduction gear to the force flow in the power 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 the separation clutch is closed. In addition, torque shocks may be introduced into the power train when the separation clutch is closed, which can be perceived by shaking, vibrations or noise. Summary of the invention

[0005] The object of the present invention is to improve the prior art.

[0006] This object is achieved by a method according to the invention for operating a brake system of a vehicle, a control unit according to the invention for actuating a separating clutch, and a computer program product according to the invention having instructions.

[0007] Therefore, a method for operating a braking system of a vehicle, in particular a motor vehicle, is proposed. The braking system has at least a retarder and a disconnect clutch. The disconnect clutch is used to selectively connect and disconnect 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.

[0008] It is proposed that at least one specific driving situation of the vehicle which is present at a user request for a braking operation of the retarder is learned or has been learned in advance. This specific driving situation is then stored. When a driving situation corresponding to the learned driving situation occurs later, the separation clutch is closed (automatically). This closing now does not require a user request again. In particular, no active braking operation of the retarder is initiated here.

[0009] In other words, the driving condition of the vehicle is recorded or has been recorded at the time when a user request for braking the retarder occurs. This driving condition is learned or has been learned. When a driving condition corresponding thereto occurs again later, this is recognized and the disconnect clutch is closed in advance. Thus, a subsequent user request for braking the retarder can be implemented immediately. Thus, the actuation of the retarder is predicted. Thus, it is possible to avoid that the disconnect clutch is closed more often than necessary. In other words, a learning process is carried out for the early actuation of the disconnect clutch. Thus, certain driving conditions for which a braking actuation of the retarder is usually carried out can be recorded and permanently stored.

[0010] This learning can be performed in advance in a learning process and / or can be performed during normal operation of the brake system. By learning in advance, time for learning during subsequent operation can be saved. By learning during operation, the actuation of the disconnect clutch can be further optimized. In particular, this learning can be performed by artificial intelligence. In this way, an artificial neural network for optimally closing the disconnect clutch can be formed and continuously further developed. This artificial intelligence records the current driving situation during the operation of the brake system and enables corresponding actuation of the disconnect clutch.

[0011] A user request may be understood as a request triggered by a user of the vehicle. Thus, a user request for causing a braking operation of the retarder is a request for manipulating the retarder that is triggered by a user of the vehicle. The request may occur in a conventional manner, in particular via an input device operable by the user for operating the retarder (e.g. a retarder lever or a retarder switch). Thus, a user request may be implemented as a corresponding notification in the data bus of the vehicle. Thus, in the presence of such a bus notification, there is a user request for causing a braking operation of the retarder. In this regard, a user of the vehicle is understood to be the driver of the vehicle or an operator equivalent to the driver.

[0012] A driving situation can be understood as an operating state of the vehicle and / or an environmental condition of the vehicle. The driving situation is defined in particular by a certain number of predefined characteristic values ​​determined during the operation of the vehicle. The vehicle therefore has one or more devices for determining these characteristic values. The characteristic values ​​can be recorded continuously or intermittently during the operation of the vehicle. Thus, the currently existing driving situation is determined continuously or intermittently. In the case of a user request for a braking operation of the retarder, the characteristic values ​​can also be additionally determined in real time, so that the current values ​​are always learned.

[0013] The characteristic value applicable to the driving condition of the vehicle may be one or more or all of the following items: the rotation speed of the drive motor (especially the crankshaft rotation speed), the rotation speed of the input shaft of the vehicle's gearshift transmission, the rotation speed of the output shaft of the vehicle's gearshift transmission, the speed of the vehicle, the transmission stage of the vehicle's gearshift transmission, the steering angle of the vehicle, the tilt angle of the vehicle, the load state of the vehicle, the actuation state of the vehicle's service brake, the temperature of the vehicle's service brake, the temperature of the working fluid of the retarder, the ambient temperature of the vehicle, the current and / or the road condition ahead of the vehicle. The road condition may include: the gradient of the vehicle's lane, the state of the vehicle's lane, the distance between the vehicle and the downhill slope immediately ahead, the gradient of the downhill slope, the distance between the vehicle and the speed limit zone immediately ahead, the distance between the vehicle and the crossroad immediately ahead, the distance between the vehicle and the dangerous area immediately ahead, the distance between the vehicle and other vehicles immediately ahead, the speed difference between these vehicles, the acceleration difference between these vehicles. Other suitable characteristic values, which are not mentioned here, may also be used. The characteristic values ​​are determined in particular by means of a sensor device of the vehicle, in particular an environmental sensor device. At least some of these characteristic values ​​can also be determined by means of information supplied to the vehicle from outside.

[0014] Therefore, as soon as there is a user request for the retarder to be braked, the characteristic values ​​valid at this point in time are immediately stored and / or taken into account as the basis for a learning process. The driving situation is thus learned. If there is then a comparable situation with the characteristic values, a comparable driving situation is derived. It is therefore very likely that the retarder will be operated again soon. Therefore, the disconnect clutch is then closed in the absence of a user request. However, since there is no user request at this point in time, preferably no braking operation is yet performed by the retarder.

[0015] The learned driving situations are stored, in particular, by means of a suitable, describable data memory. For this purpose, the mentioned characteristic values ​​and / or the associated characteristic value ranges are stored, in particular for the respective driving situation characterizing the driving situation. When using artificial intelligence for learning, the driving situation is stored in the data memory.

[0016] In particular, a comparable driving situation exists only when the characteristic value for the currently existing driving situation completely matches the characteristic value for the learned driving situation. However, a comparable driving situation may exist even if the characteristic value for the currently existing driving situation matches the characteristic value for the learned driving situation within a certain tolerance range (characteristic value range). In this case, a tolerance range (characteristic value range) of its own may be provided for each characteristic value.

[0017] 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.

[0018] The reducer is designed in particular (but not necessarily) as a hydraulic reducer. The hydraulic reducer 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 reducer 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 reducer. In the braking operation, the rotor moves relative to the stator or the mating rotor, thereby generating a fluid flow. This fluid flow has a braking effect on the rotor. The rotor can be connected to the powertrain by a separation clutch. Therefore, the reducer can generate 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 reducer is preferably emptied. Before, after or during the closing of the separation clutch, in order to prepare the reducer, the working chamber is at least partially filled with a working fluid. Subsequently, the setting of the braking power of the reducer can be achieved by setting the distance between the rotor and the stator (or between the rotor and the mating rotor), or this can be achieved by setting the amount of working fluid located in the working chamber.

[0019] 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.

[0020] 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.

[0021] Preferably, a plurality of specific driving situations of the vehicle are recorded, in which a user request for a braking operation of the retarder is respectively present. These driving situations are respectively learned and thus stored. This can also already be realized in advance. When a driving situation corresponding to one of the learned driving situations occurs later, the disconnect clutch is closed (automatically). Thus, the disconnect clutch can be closed in advance in a plurality of driving situations. Thus, timely and meaningful actuation of the disconnect clutch can be learned.

[0022] It can be provided that a driving situation or a driving situation equivalent thereto must coexist with a corresponding user request for a braking operation of the retarder several times in order to learn such a driving situation. In particular, a driving situation or a driving situation equivalent thereto must coexist with a corresponding user request for a braking operation at a predetermined frequency (e.g. 10 to 20 times) for this purpose. Thus, only driving situations that require the closing of the separation clutch with a high probability are learned. This prevents the separation clutch from being closed unnecessarily often.

[0023] If no user request for braking the retarder occurs after the proposed closing of the disconnect clutch, the disconnect clutch can be opened again. This can be requested in particular after a certain time span has elapsed after the closing. This time span can be preset, for example, it can be 2 to 5 minutes. The time span can also be determined depending on the mentioned characteristic values ​​or other variables. In this way, it is prevented that the disconnect clutch is opened for an unnecessary long time.

[0024] It is also possible to store or take into account situations in which no user request has occurred. As long as this situation occurs multiple times for a learned driving situation or one of a plurality of learned driving situations, it can be proposed that the learned driving situation is deleted or otherwise disabled. As a result, the separation clutch is not automatically closed again in the future when a comparable driving situation exists. According to the proposal, the same driving situation can be learned again or enabled again later. Accordingly, it is determined whether a user request for a braking operation of the retarder has occurred after the separation clutch has been closed, based on a driving situation that subsequently occurs that is comparable to the learned driving situation. If this situation does not apply once or multiple times (i.e., no user request for a braking operation has occurred), the learned driving situation is deleted or disabled. It can be proposed here that the situation in which no user request has occurred must occur at a predetermined frequency (e.g., 10 to 20 times) in order to delete or disable the stored driving situation. Therefore, only driving situations that require the separation clutch to be closed with a greater probability are kept learned (stored). It is also possible to prevent the separation clutch from being closed unnecessarily often.

[0025] Preferably, at least one (and possibly more) specific driving conditions of the vehicle are pre-stored. That is, the at least one driving condition is pre-installed. The purpose of the pre-stored driving condition corresponds to the purpose of the driving condition stored during operation of the vehicle. Therefore, the pre-stored driving condition can be in the same data memory as the driving condition learned during operation. Correspondingly, when a driving condition corresponding to the stored driving condition occurs later, the separation clutch is also closed. This can shorten the time for learning the driving condition. At least one pre-stored driving condition can be processed in the same way as the driving condition learned during operation of the vehicle. Therefore, it can be proposed that the pre-stored driving condition can be deleted or disabled in another way in the described manner.

[0026] Preferably, the separation clutch is operated (automatically) depending on a plurality of influencing variables. Therefore, a plurality of given conditions can be considered. These influencing variables can be given different priorities. Here, one of the plurality of influencing variables is the mentioned presence of a driving condition that is comparable to the learned driving condition or the pre-stored driving condition. Therefore, the separation clutch is automatically closed only when it is likely that the reducer will be used. Another influencing variable is the presence of a user request for the reduction gear to perform a braking operation. When this user request exists, the separation clutch should be closed immediately, because this is a prerequisite for the reduction gear to perform a braking operation. Here, operating the separation clutch is not only understood as the targeted operation of the separation clutch in the sense of disconnection and closure, but also as the targeted maintenance of the separation clutch in the disconnected state and the closed state. In order to maintain, in particular, the received request for changing the clutch state is not implemented in a targeted manner. So, for example, the request for closing the separation clutch is ignored.

[0027] One or more of the plurality of influencing variables may be: a traction maneuver of the vehicle, in which the retarder is disconnected; a coasting maneuver of the vehicle, in which the retarder is coupled; altitude information of the road section ahead of the vehicle (map data); one or more bends on the road section ahead of the vehicle (map data); one or more roundabouts on the road section ahead of the vehicle (map data); an entry point on the road section ahead of the vehicle (map data); one or more speed limits on the road section ahead of the vehicle (map data); a distance to a preceding traffic participant (driver assistance system); a traffic jam on the road section ahead of the vehicle (driver assistance system). These influencing variables thus enable automatic actuation of the disconnect clutch. The proposed procedure makes it possible to automatically actuate the disconnect clutch even if these influencing variables are not present.

[0028] In particular, at least one further (negative) influencing variable is provided, which (if present) substantially prevents the actuation of the separating clutch, preferably the closing of the separating clutch. For this purpose, these influencing variables can be given a correspondingly high priority. Such an influencing variable can be the wear state of the reducer or the operating fluid of the reducer or the separating clutch. Such an influencing variable can be a recognized defect of the separating clutch or the reducer. It can also be provided that, in the presence of one or more such influencing variables, the closed separating clutch is immediately completely or partially disconnected. In this way, an impermissible operation of the reducer and / or the separating clutch can be reliably prohibited.

[0029] Preferably, user requests for braking the retarder are recorded and learned in a user-dependent manner. It is thus recognized which user of the vehicle has made a user request for the retarder. It is therefore also possible to record and learn in a user-dependent manner under which driving conditions no user request for braking the retarder has occurred. In this way, a specific user profile (Nutzerprofil) for operating the separation clutch can be created and can also be continuously adapted. Thus, different use behaviors of the retarder by different users or user types of the vehicle can be taken into account. The user of the vehicle and the user type to which it may belong can be identified in any manner, for example in commercial vehicles by means of a driver card provided for the digital driving recorder. When using user types, a plurality of different users can be assigned to one user type.

[0030] Preferably, as already explained above, a specific driving condition of the vehicle that exists at the request of the user is recorded. Now, this driving condition is assigned to a specific user or user type of the vehicle. Thus, the combination formed by the user request and the specific driving condition is personalized. In particular, the driving condition is assigned to the vehicle user who just operates the vehicle in this driving condition. The user request is implemented by this user. Subsequently, this driving condition is learned accordingly and personalized. In this way, a user profile for the separation clutch can be easily created. Therefore, preferably, when a driving condition corresponding to the learned driving condition occurs later, the separation clutch is closed (automatically) only when the current user of the vehicle is the user assigned to the learned driving condition, or only when the current user of the vehicle belongs to the user type assigned to the learned driving condition. In this way, the user profile can be easily taken into account when operating the separation clutch. In this regard, the current user is the user who currently uses the vehicle or the person who is recognized as the current user by the vehicle.

[0031] In addition to the method, a control unit is also proposed. The control unit is used to actuate the disconnect clutch, which is used to couple 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 coupled to the force flow. In addition, the control unit can be used to actuate the retarder.

[0032] The control unit is designed to carry out the proposed method. The control unit therefore has in particular a data memory and a corresponding computing device in order to process the variables and characteristic values ​​mentioned in the context of the proposed method and subsequently generate corresponding signals for actuating the separation clutch. The data memory is then used to store specific driving situations.

[0033] When at least one pre-stored driving situation is used, this driving situation is pre-installed in the data memory. This pre-installation takes place in particular during the production of the gear unit, when the functional software is first implemented on the control unit. This may also include installing or implementing an artificial intelligence for learning the driving situation. The artificial intelligence is preferably pre-trained so that it already contains the pre-stored driving situation. This pre-installation takes place in particular in the end-of-line area of ​​the gear unit assembly line.

[0034] A computer program product is also proposed. The computer program product has instructions, which, when executed by a computing unit, cause the computing unit to perform the proposed method. The computing unit then controls or regulates the operation of the brake system according to the proposed method. The computing unit can be, for example, a computer or a microcontroller, or can include such a computer or microcontroller. The computing unit can be, for example, part of the proposed controller. The computer program product can be an electronic data memory on which instructions are stored electronically. This data memory can also be used to store and / or pre-store driving conditions as mentioned. The computer program product is especially implemented for exclusive use in the mentioned controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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.

[0036] Figure 1 A vehicle powertrain having a couplable and decouplable speed reducer is shown,

[0037] Figure 2 An application scenario of a vehicle having a couplable and decouplable reducer is shown. DETAILED DESCRIPTION

[0038] Figure 1 The power train of a vehicle, in particular a motor vehicle, in particular 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 in particular a multi-stage shift transmission. Therefore, the transmission can be, for example, an automated shift transmission or an automatic transmission. A drive axle 3 of the power train is arranged on the driven side of the transmission 2. The drive axle is connected to the drive wheel 4. Therefore, the drive force and therefore the corresponding drive torque and the corresponding drive 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 road surface. Therefore, in the traction operation of the vehicle, the vehicle can be driven by the drive motor 1.

[0039] 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.

[0040] A retarder 6 is also provided in the vehicle as a continuous brake. The retarder 6 and the service brake 5 can each be part of a common brake system. However, the retarder 6 can also be implemented as a separate brake system. The retarder 6 can be a component of the transmission 2.

[0041] The reducer 6 is designed as a hydraulic reducer by way of example. Therefore, the 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 mode of the reducer 6 described below.

[0042] 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 drive shaft 6C of the reducer 6 connected to the rotor 6A. The braking torque may depend on the filling degree of the working chamber by 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.

[0043] 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.

[0044] It should be noted here that the retarder 6 does not yet produce a braking effect in the coupled state in the sense of braking. 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.

[0045] A control unit 8 is provided for actuating the clutch 7. The control unit 8 is also used, in particular, to actuate the retarder 6 itself, ie, to set the braking effect of the retarder 6, in particular by setting the filling level of the retarder 6 and / or the distance between the rotor 6A and the stator 6B.

[0046] Information and commands can be supplied to the controller 8. To control the clutch 7, the controller 8 processes the information and commands received therein by means of a logic circuit and outputs corresponding commands to the clutch 7. The actuator assigned to the clutch 7 then implements the commands to the clutch 7. The same applies to the retarder 6. The commands of the controller 8 to the retarder 6 are implemented by means of the actuator assigned to the retarder 6.

[0047] When the user of the vehicle manually requests the retarder 6 to perform a braking operation, a corresponding user request is generated. This corresponding user request can be generated by the controller 8 itself. However, this corresponding user request can also be generated by an input device for the user of the vehicle and transmitted to the controller 8. This input device is used for the user to operate the retarder 6, in particular for manually presetting the braking torque of the retarder 6. In order to subsequently realize the braking operation of the retarder 6, the separation clutch 7 must first be closed. This takes a certain amount of time.

[0048] Therefore, it is proposed that the separation clutch 7 is automatically closed when the retarder 6 is likely to be braked. This is especially the case when the user has requested the retarder 6 to brake in a previous comparable driving situation. Here, the controller 8 performs an evaluation.

[0049] For this purpose, the control unit 8 learns the specific vehicle driving condition that prevails when a user request for braking the retarder 6 is present or received and therefore stores this driving condition in the data memory 8A of the control unit. When a driving condition that is equivalent to the learned driving condition occurs later, the separation clutch 7 is closed in advance. Then, if the user actually requests the retarder 6 to perform a braking operation in this later driving condition, the retarder 6 can be used for braking operation immediately. It is then not necessary to first wait for the time for closing the separation clutch 7. This can be provided for any number of driving conditions. It can then also be determined whether a user request for braking the retarder 6 actually occurred after closing the separation clutch 7. If this is not the case, the learned driving condition can be deleted again or disabled in another way.

[0050] It can be provided that such a situation must be present several times in order to learn the corresponding driving situation and thus store it in the data memory 8A, and / or that the driving situation that has been learned is subsequently deleted (or disabled) from the data memory 8A again. In this way, the control unit 8 autonomously learns for the purpose of prematurely closing the separation clutch 7. Since the use of the retarder 6 depends largely on the individual user of the vehicle, it can also be provided that the driving situations are stored in the data memory 8A in a user-dependent manner and that these driving situations can also be deleted again. Thus, a personalized user profile for the operation of the retarder 6 can be generated over time. In order to shorten the learning phase of the control unit 8, it can be provided that predefined driving situations are pre-stored (i.e. pre-installed) in the data memory 8A. These pre-stored driving situations have the same function as the driving situations stored in the driving operation of the vehicle.

[0051] This learning is carried out in particular with the aid of artificial intelligence. The artificial intelligence can be pre-trained and therefore already has learned / pre-installed driving situations when installed on control unit 8 .

[0052] The respectively existing driving situation of the vehicle can be detected by means of suitable sensors, in particular by means of sensors in the drive train of the vehicle and / or by means of an environmental sensor system of the vehicle.

[0053] exist Figure 2 An exemplary scenario for using the disconnect clutch 7 is shown in FIG. Figure 2 In the upper area, a vehicle 9 is shown, which is traveling in the direction of the arrow on a roadway 10. At a distance X in front of the vehicle 9 in the direction of travel, the roadway 10 has a downhill slope 11 with a certain gradient. Figure 1 The power transmission system as well as the reducer 6, the separation clutch 7 and the controller 8.

[0054] The vehicle 9 is able to determine its driving conditions. The driving conditions also include the distance X from the downhill slope 11 and the gradient of the downhill slope. Therefore, the vehicle 9 also has a device for determining the distance X. For this purpose, the vehicle 9 can, for example, have a satellite navigation device, and the satellite navigation device can access corresponding road condition information in the environment of the vehicle 9. As a result, the vehicle 9 also knows the gradient of the downhill slope 11.

[0055] It follows that the vehicle 9 was already in a comparable driving situation beforehand and that a user request for a braking operation of the retarder 6 occurred at that time, so that the driving situation at that time is now learned and thus stored in the data memory 8A of the controller 8. However, as an alternative to this, such a driving situation can also be predefined and thus can be prestored in the data memory 8. In any case, now, in Figure 2 There is a driving condition corresponding to the existing driving condition in the data storage device 8A.

[0056] exist Figure 2 In the lower region of FIG. , the activation of the retarder 6 and the separating clutch 7 is shown in the form of curves T, T* and R, R* at the respective route position and time position of the vehicle 9 .

[0057] The curve T here represents a request (signal) for actuating the separating clutch 7 , wherein the value “0” corresponds to a request for opening the separating clutch 7 and the value “1” corresponds to a request for closing the separating clutch 7 .

[0058] The curve T* represents the actual actuation state of the separating clutch 7 , wherein the value “0” corresponds to an open separating clutch 7 and the value “1” corresponds to a closed separating clutch 7 .

[0059] The curve R here represents a request (signal) for causing the retarder 6 to perform a braking operation, wherein the value "0" corresponds to a request for no braking torque to be provided (i.e., no braking operation should actually be performed), and wherein the value "1" corresponds to a request for a certain braking torque to be provided (i.e., braking should actually be performed with the aid of the retarder 6).

[0060] The curve R* represents the actual actuation state of the retarder 6 , wherein the retarder 6 generates no braking torque at the value “0” and wherein the retarder generates a certain braking torque at the value “1”.

[0061] exist Figure 2 In the embodiment, before time t1, neither the retarder 6 nor the service brake 5 is requested to be braked. The separation clutch 7 is firstly disengaged.

[0062] At time t1, it is recognized that the current driving condition of the vehicle 9 corresponds to the driving condition existing in the data memory 8A of the retarder controller 8. Therefore, the retarder 6 will be braked with a high probability. Correspondingly, at time t1, it is requested to close the separation clutch 7. Therefore, the value of the curve T changes from 0 to 1 at time t1.

[0063] At time t2, a request is made to close the separation clutch 7. Therefore, the value of the curve T* changes from 0 to 1 at time t2. The time span between t1 and t2 is required for mechanically coupling the reducer 6 to the drive train of the vehicle 9 by means of the clutch 7. From time t2, the reducer 6 is coupled via the clutch 7 and is thus ready.

[0064] At time t3, the vehicle 9 is at the beginning of a downhill slope. The retarder 6 has not been braked yet.

[0065] At time t4, a request is issued by the user of the vehicle 9 for the retarder 6 to perform a braking operation. Therefore, the value of the curve R changes from 0 to 1 at time t3. This user request is output by the controller 8 to the retarder 6. Shortly thereafter, the retarder 6 begins to generate the corresponding braking torque. This is achieved in a ramp-like manner. Therefore, the value of the curve R* changes from 0 to 1 until time t5. At time t5, the retarder 6 generates the entire braking torque requested by the user of the vehicle 9.

[0066] In this way, a predictive closing of the separator clutch 7 can be easily achieved. Subsequently, the braking operation of the retarder 6 can be started without significant delay.

[0067] List of Reference Numerals

[0068] 1 Drive motor

[0069] 2 Transmission

[0070] 3 Drive axle

[0071] 4 Drive wheels

[0072] 5 Service brakes

[0073] 6 Reducer

[0074] 6A Rotor

[0075] 6B Stator

[0076] 6C Drive shaft

[0077] 7 Disengagement clutch

[0078] 8 Controller

[0079] 8A Data Memory

[0080] 9 Vehicles

[0081] 10 Lanes

[0082] 11 Downhill

[0083] X distance

[0084] T, T* curve (disengagement clutch)

[0085] R, R* curve (reducer)

[0086] t time

[0087] t1,…t5 time points (road section locations)

Claims

1. A method for operating a braking system (5, 6) of a vehicle (9), the braking system having at least one retarder (6) and a separating clutch (7), the separating clutch being used to couple and disconnect the power flow of the retarder (6) to a drive train (1, 2, 3, 4) of the vehicle (9), It is characterized in that learning or having learned the driving condition of the vehicle (9) present at the user's request (R) for causing the retarder (6) to perform a braking operation (R*); and When a driving condition corresponding to the learned driving condition occurs later, the separation clutch (7) is closed. If no user request for braking the retarder occurs after the separation clutch is closed, the separation clutch is opened again.

2. The method according to claim 1, wherein it is determined whether a user request (R) for a braking operation (R*) of the retarder (6) occurs after the separation clutch (7) is closed, wherein If this is not the case one or more times, the learned driving situation is deleted or disabled.

3. The method according to claim 1 or 2, wherein a driving condition of the vehicle (9) is pre-stored, and wherein the separating clutch (7) is closed when a driving condition corresponding to the pre-stored driving condition occurs later.

4. The method according to claim 1, wherein the separating clutch (7) is actuated as a function of a plurality of influencing variables, wherein one of the plurality of influencing variables is the presence of a driving situation that corresponds to the learned driving situation.

5. The method according to claim 3, wherein the separating clutch (7) is actuated as a function of a plurality of influencing variables, wherein one of the plurality of influencing variables is the presence of a driving situation that corresponds to a pre-stored driving situation.

6. The method according to claim 1, wherein a user request (R) for causing the retarder (6) to perform the braking operation (R*) is recorded in a user-dependent manner.

7. A method according to any one of claims 1-2, wherein the driving condition of the vehicle (9) existing at the user request (R) is recorded, and the driving condition is assigned to a specific user or a specific user type of the vehicle (9) and learned.

8. The method according to claim 7, wherein, when a driving situation corresponding to the learned driving situation subsequently occurs, the separator clutch (7) is closed only if: When the current user of the vehicle (9) is assigned to the user of the learned driving condition, or When the current user of the vehicle (9) belongs to the user type assigned to the learned driving situation.

9. A controller (8) for operating a separation clutch (7) for coupling and disconnecting a reduction gear (6) with a power train (1, 2, 3, 4) of a vehicle (9), characterized in that: The control unit (8) is designed to carry out the method according to one of the preceding claims. 10 . A computer program product having instructions which, when executed by a computing unit, cause the computing unit to carry out the method according to claim 1 .

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