Method and vehicle system for moment-limited vehicle control and correspondingly equipped motor vehicle

Abstract

The invention relates to a method (11) for controlling a motor vehicle (1) that can be longitudinally guided in a manual operating mode by a driver (2) and in an automated operating mode by a driver assistance system (3). In the method (11), in a corresponding predefined control mode and while the motor vehicle (1) is longitudinally guided by the driver assistance system (3) in automated operating mode, the torque that would be actuated in the current driving situation without any driving longitudinal guidance intervention by the driver assistance system (3) in manual operating mode without any manual longitudinal guidance intervention by the driver (2) is determined. The actuating position of a driver assistance system (FAS) torque for regulating a target acceleration requested by the driver assistance system (3) is then limited to the determined torque in the current driving situation.The invention also relates to a vehicle system (7) set up for the method and a motor vehicle (1) equipped therewith.

Description

The present invention lies in the field of automotive engineering and relates to a method for controlling a motor vehicle that is configured for both manual longitudinal control by a driver and for at least assisted or at least partially automated longitudinal control by a driver assistance system. The invention also relates to a vehicle system configured for the method and a motor vehicle equipped therewith. Motor vehicles are increasingly being equipped with functions and systems to improve user comfort or even to automate driving. This can ultimately lead to increased complexity, which is not always advantageous, as well as higher costs and a greater likelihood of unexpected or undesirable behavior. Examples of such assistance systems include adaptive cruise control (ACC) and regenerative braking (SCBA). ACC is permitted, at least when a preset target or set speed is higher than the current actual speed and no vehicles or obstacles ahead prevent this, to also propel the vehicle, thus generating positive torques that increase the vehicle's speed.In contrast, a SRA (Sensitive Brake Assist) is designed solely to vary deceleration, for example, by increasing or decreasing recuperation to generate larger or smaller negative moments that decelerate and thus reduce the vehicle's speed. While using an ACC (Adaptive Cruise Control) chain to implement the functionality of an SRA could, in principle, contribute to reducing complexity and costs, this is not readily feasible due to the potential for resulting accelerations during SRA operation. Similarly, there may be situations in which an ACC should not propel the vehicle, i.e., should not increase speed, for example, if the ACC itself or corresponding sensors for environmental perception are malfunctioning, or similar issues arise. Furthermore, a driver assistance system or function may be required to determine the appropriate speed.The requested target acceleration does not automatically allow for a decision as to whether it will or should result in positive outcomes, as external disturbances or influences, such as wind and other environmental factors and / or inclines or declines, can affect this. While efforts are already underway to improve the control of assistance systems and braking and drive systems, further improvements are still needed. As one approach, DE 10 2009 020 794 A1 describes a method for coordinating the powertrain of a motor vehicle. This method aims to consider as many individual influences on the acceleration and / or speed of the vehicle as possible and to comprehensively integrate vehicles with multiple drive units into the coordination process. To this end, several target accelerations are specified, each with assigned priority information. Depending on the priority information, the individual target accelerations are transformed into a target acceleration for the vehicle. Based on the target acceleration and an actual acceleration, a target wheel torque is determined, and requirements for the torque of the drive and / or braking units are set accordingly. EP 2 371 647 B1, for example, deals specifically with recuperation. It describes the control of a motor vehicle's energy recovery system for recuperating kinetic energy using an electromechanical converter. A target acceleration for the vehicle and information about the road gradient at the vehicle's location are provided. Based on this, a quantitative measure of recuperation is determined, and the energy recovery system is controlled accordingly. The complexity and challenges of vehicle control can be further increased by allowing both a driver assistance system or vehicle function and the driver to intervene in vehicle control simultaneously. For example, WO 2017 / 084 977 A1 describes a method for modifying the recuperation effect of a motor vehicle during coasting. This method involves detecting when the brake pedal is pressed while driving downhill and switching to a recuperation mode with increased recuperation in response. In this increased recuperation mode, even after the brake pedal is released during coasting, the recuperation remains enhanced. This is intended to enable improved recuperation settings in a motor vehicle. The object of the present invention is to enable, in a simple manner, robust operation of a motor vehicle that can be driven longitudinally manually and at least assisted or at least partially automatically. This problem is solved by the subject matter of the main claim and the dependent claims or independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims. The method according to the invention can be used for or during the control of a motor vehicle that is configured both for manual longitudinal control by a driver in a manual operating mode and for at least assisted or at least partially automated longitudinal control by a driver assistance system in an automated operating mode. In particular, the driver assistance system and / or ultimately, i.e., directly or indirectly, a braking and / or drive system of the motor vehicle can be controlled. The driver assistance system can include, implement, or provide one or more driver assistance functions, such as an ACC function and a SRA function, or the like. The SRA function can, in particular, control recuperation, but—at least outside of a near-standstill speed range—Within the creep speed range, no positive torques—that is, torques that increase the vehicle's speed—are generated. In contrast, the ACC function, for example, can request or generate such positive torques—especially regardless of speed, i.e., across all speed ranges. Such driver assistance functions, which can request or generate positive torques that increase speed, can also be referred to here as drive-related driver assistance functions. According to the invention, in a predetermined or predefined control mode and while the motor vehicle is being driven in automated operating mode, at least also by the driver assistance system (i.e., while the driver assistance system is active), the system automatically determines, in particular continuously, which torque(s), i.e., braking and / or drive torque(s), would be applied in the current driving situation if the motor vehicle were instead operated in manual operating mode without manual longitudinal control input from the driver—and in particular also without any driving longitudinal control input from the driver assistance system or a drive assistance function. The torque thus determined can therefore be, for example, the pedal point or accelerator pedal torque present in a corresponding driving situation in manual operating mode.This allows, for example, the determination of whether the vehicle would creep at a given operating point, and / or what recuperation torque would be present, or similar information. Manual longitudinal control intervention by the driver can involve the operation of a brake control and / or an acceleration control, specifically a brake pedal and / or an accelerator pedal. Therefore, it is possible to determine, for instance, how the vehicle would behave in a given driving situation while coasting with the adaptive cruise control (ACC) and / or other driver assistance functions, which can also generate positive drive torques (i.e., speed-increasing torque), inactive or deactivated (i.e., not intervening in longitudinal control) and / or other driver assistance functions. This analysis assumes that the recuperation function remains active or effective. In a further step of the inventive process, the actuator position, i.e., the generation of a driver assistance system (FAS) torque for adjusting or setting a target FAS acceleration determined or requested by the driver assistance system, in particular a driver assistance function that can also generate positive drive torques, is automatically capped, i.e., limited, to the determined torque in the current driving situation in the corresponding predefined control mode. The FAS torque can be a torque, i.e., a torque or drive torque, particularly a positive one, that would be applied by a corresponding actuator or by the drive system or the braking and drive system of the motor vehicle to set the target FAS acceleration if no limitation existed or were active. This FAS torque can then correspond to a total torque applied by the actuator or to a torque set by the driver assistance system.The corresponding situation-dependent driving assistance function is a component of a total applied torque. A brake actuator can, for example, be or include a hydraulic friction brake. The drive system, or a drive actuator, can, for example, be or include an electric drive motor. Such an electric drive motor can generate positive torques, which increase the vehicle's speed relative to its surroundings; these are referred to here as drive torques. Likewise, such a drive motor can generate negative torques, which reduce the vehicle's speed relative to its surroundings; these are referred to here as braking torques. Depending on the situation, the electric drive motor can therefore be operated or used as a motor or as a generator, and thus function as a brake actuator or a drive actuator. The fact that the driver assistance system requests a specific target acceleration, namely the FAS target acceleration, can mean, for example, that the driver assistance system calculates a specific target deceleration of the vehicle for at least assisted or at least partially automated longitudinal guidance or for the execution of a specific driving maneuver and then outputs a corresponding control or request signal, for example to an actuator to implement the request, i.e. the requested FAS target deceleration by setting a corresponding torque, or to a control unit, for example, depending on the situation, a brake and / or drive control unit of the vehicle or the like. Depending on the implementation of the present invention, the driver assistance system itself can be controlled or adjusted to limit the actuator position of the FAS torque such that it requests a maximum target deceleration achievable with the determined torque, i.e., the limited FAS torque, or that it requests a maximum FAS torque corresponding to the determined torque. Likewise, the braking and / or drive system can be controlled or adjusted such that, regardless of the request from the driver assistance system, it provides a maximum of the determined torque or limits a portion of the total torque to be provided, allocated to the driver assistance system, to the determined torque. For example, a corresponding parameter value or a control flag of the driver assistance system and / or the braking and / or drive system or a corresponding control unit can be set to limit the FAS torque. The FAS moment can be limited, for example, until a predefined end or termination condition is reached or fulfilled. When this is the case, the limitation can be automatically lifted, allowing the driver assistance system, or its longitudinal control unit, particularly the acceleration controller, to resume fully dynamic, i.e., controlling, longitudinal steering of the vehicle. The FAS torque limit can be applied independently of any longitudinal control input from the driver, particularly accelerator pedal operation. In other words, even with the FAS torque limited, the driver can still influence the longitudinal control, i.e., the overall torque setting, by manually operating the corresponding controls, even beyond the FAS torque limit or in a positive and / or negative direction. Similarly, the FAS torque can also be limited even if the driver does not actively intervene in the vehicle's longitudinal control. To implement the procedure, continuous monitoring of the driving situation and / or monitoring for activity or longitudinal control interventions by the driver assistance system (DAS), i.e., requested DAS target accelerations, can be carried out. Likewise, continuous monitoring for longitudinal control interventions by the driver can be performed. The present invention enables a simple, robust, and safe implementation of multiple driver assistance functions, which can then, in particular, utilize at least partially the same components or the same chain of operations. For example, if the specified control mode is assigned to the headlight washer system (SRA), the SRA functionality can then be implemented by the same driver assistance system that also provides the adaptive cruise control (ACC) functionality, without resulting in unintended positive accelerations. This eliminates the need for completely separate components or systems for the ACC and the SRA. Flexible use of the corresponding control mode is also possible.This allows it to be used or activated in other situations where, for example, the ACC or another potentially torque-generating driver assistance function should not produce positive acceleration or torque beyond what the driver would experience in the same or a comparable driving situation without manual intervention. Thus, with reduced component and / or cost requirements, both the implementation of various driver assistance functions and a particularly high degree of flexibility and safety can be achieved. In one possible embodiment of the present invention, the determined torque, which would be applied in manual operating mode without longitudinal guidance interventions by the driver assistance system or a drive assistance function and the driver in the respective current driving situation, is or comprises a recuperation torque. Such a recuperation torque can be an overall decelerating torque by which usable energy, in particular electrical energy, is generated in the motor vehicle from the kinetic energy of the motor vehicle, for example, for charging a traction battery or the like. However, the recuperation torque can, in principle, be generated in various ways depending on the situation, for example, depending on different quantities or parameter values ​​or settings, or on the speed, or on friction, or the like.The recuperation torque can also vary depending on the situation, meaning that its magnitude may differ in different driving situations and / or it may point or act in different directions, for example, forwards or backwards in the longitudinal direction of the vehicle depending on the direction of travel or the incline or decline of the surface. Because the determined torque is or includes a recuperation torque, the present invention can, for example, effectively implement and provide the SRA functionality. In a further possible embodiment of the present invention, the driving situation is characterized or determined at least by the speed of the motor vehicle and / or the acceleration (positive or negative) of the motor vehicle and / or the direction of travel of the motor vehicle and / or the local gradient (positive or negative) of the road surface and / or a recuperation level set in the motor vehicle. The set recuperation level can, for example, be a degree or intensity of recuperation or a maximum recuperation power. For example, the recuperation level can be set manually, i.e., in particular by the driver, or by a driver assistance system. The quantities or parameters proposed here can be particularly decisive for the behavior of the motor vehicle.This allows for a comprehensive characterization of the driving situation and, consequently, a particularly precise determination of the torque that would be applied in manual mode under the given driving conditions. Furthermore, it ensures that, even in highly varied driving situations, the driver assistance system, for example, does not generate more torque in the specified control mode than the driver would experience in manual mode without manual longitudinal control intervention. This results in particularly safe and robust vehicle operation. Depending on the requirements or needs, additional parameters that could influence the calculated torque can also be considered for a more detailed or refined characterization of the driving situation. In a further possible embodiment of the present invention, the actuating position, i.e., the generation of the FAS torque for adjusting or setting the FAS target acceleration determined by the driver assistance system in the current driving situation, is limited only upwards, i.e., only in the direction of larger positive torques that increase the vehicle's speed more significantly. In other words, the determined torque here functions only as a limit or threshold for the positive acceleration, the drive torques, or the drive torque component assigned to the driver assistance system. Thus, despite or even with active limitation, negative, i.e., decelerating, FAS target accelerations could still be implemented, if necessary, without a corresponding absolute torque limit. This allows for a particularly high level of safety, since positive accelerations are generally not affected.Corresponding moments can pose a greater danger than negative accelerations, i.e., decelerations or corresponding moments. In a further possible embodiment of the present invention, the limitation or deactivation of the FAS torque occurs only in the predefined control mode. Outside of this control mode, i.e., when it is deactivated or when another control mode is used, the motor vehicle, the driver assistance system, and / or the braking and / or drive system of the motor vehicle can be controlled or operated differently in a situation where the limitation would occur in the predefined control mode. In the embodiment of the present invention proposed here, the predefined control mode is requested or set by the driver assistance system or is set automatically depending on a functional state or behavior of the driver assistance system.The latter can mean, in particular, that the specified control mode is set or activated in the event of a degradation of the driving assistance system, especially a partial degradation, i.e., limited to one of several driving assistance functions or not encompassing or affecting all driving assistance functions of the driving assistance system, and / or a corresponding sensor system of the motor vehicle that provides input data or a data basis for the driving assistance system. In other words, the driver assistance system or a driver assistance function can, if necessary, decide for itself whether and when the control mode is or should be active. For example, the headlight washer system (SRA) can request or set the control mode when it is or should be active. Similarly, the control mode can be set automatically, for example, if the adaptive cruise control (ACC) or a sensor necessary for its proper functioning is malfunctioning, so that the driver assistance system or the ACC can no longer accelerate the vehicle more strongly than would be the case, for example, with the SRA or a regular creep or recuperation function in manual mode without manual longitudinal control intervention.In the event of a corresponding degradation, the driver assistance system, or for example one, several, or all driver assistance functions that can or may request larger positive accelerations during regular or error-free operation, can be deprived of the corresponding possibility or authorization for such drive control by setting or activating the specified control mode. The embodiment of the present invention proposed here can improve safety, since, for example, the driver does not have to activate the control mode himself, which requires a level of competence and attention that may not always be present, or would typically be slower than automatic activation. In a further possible embodiment of the present invention, at the moment the limit actually takes effect, a longitudinal control controller of the driver assistance system and / or the actual set FAS torque, i.e., a corresponding FAS component or contribution to a total set torque, is frozen. The longitudinal control controller can, in particular, be an acceleration controller or, for example, a speed controller. The fact that the limit takes effect here means, in particular, that a torque greater than the determined torque would be necessary, or would be set without the limit, to regulate, i.e., to implement or realize the requested FAS target acceleration. Freezing in this context can mean that the FAS torque is fixed at the corresponding value or is no longer subject to further or free control, or at least...The driver assistance system (DAS) is only exempt from increasing the torque. The frozen DAS torque can then, for example, be set or kept constant until further notice. Accordingly, the DAS, or the corresponding driver assistance function responsible for the frozen torque, can no longer actively regulate or positively accelerate the longitudinal control of the vehicle. Freezing the longitudinal control controller can mean, for example, that it is continuously reset, that its initial value is enforced, or that a control loop is interrupted or stopped. The freezing can last, for example, until a termination or end condition mentioned elsewhere is met.The embodiment of the present invention proposed here can provide a simple and effective means of implementing the limitation and, for example, depending on the configuration of the termination condition, prevent erratic or rapidly changing behavior of the vehicle. This can improve driving comfort. In a possible further development of the present invention, the longitudinal control of the driver assistance system and / or the actual set FAS torque is frozen for as long as the limit is in effect, i.e., for as long as the torque required to regulate the FAS target acceleration is at least equal to the determined torque or the frozen value, and / or for as long as an active longitudinal control intervention by the driver continues. Accordingly, the freezing can be ended, and thus the active control of longitudinal guidance by the driver assistance system can be released again, when the FAS target acceleration or the FAS torque actually required for it falls below the determined torque, i.e., below the limit, and / or when the driver ends their longitudinal control intervention, i.e., when they no longer actuate a corresponding control element such as the brake pedal and / or the accelerator pedal.This allows for a certain degree of flexibility and the possibility of assisted or at least partially automated braking maneuvers to be maintained, while at the same time preventing the driver assistance system and the driver from acting as competing controllers, i.e., being active at the same time. In a further possible embodiment of the present invention, in a first variant, if the set FAS torque is greater than the determined torque at the time the limit actually takes effect, the set FAS torque is gradually reduced to the determined torque. In other words, the set FAS torque is reduced to the determined torque over a certain period of time, for example, continuously or with a predetermined maximum gradient, and is not set to the determined torque instantaneously or abruptly. This gradual reduction or adjustment of the set FAS torque can be controlled in a predetermined manner and is therefore not subject to free control by the driver assistance system. The freezing of the FAS torque described elsewhere can, in this context, mean, for example, that the FAS torque is no longer freely controllable by the driver assistance system from the moment the limit actually takes effect, and / or that the FAS torque is only frozen once the determined torque has been reached, i.e., once the gradual adjustment or change of the actual FAS torque has been completed. Additionally or alternatively, in a second variant, the set FAS torque is gradually changed to a new value, for example, from the frozen value described elsewhere, either during or immediately after deactivation of the limit and / or the specified control mode. The set FAS torque can then be gradually changed, for example, to zero or to a target value calculated at that time, which is necessary to regulate the desired FAS deceleration currently requested by the driver assistance system. Here, too, the corresponding change or adjustment of the actual set FAS torque occurs continuously over a certain period of time or with a predefined maximum gradient, and not instantaneously or abruptly.Furthermore, in this second variant, the change or adjustment of the FAS torque to the new target value to be set can also be controlled in a predetermined manner, i.e., it is not subject to free control by the driver assistance system. The proposed embodiment of the present invention prevents longitudinal jerks and sudden changes in the vehicle's load or stress. This enables particularly comfortable, safe, and gentle operation of the vehicle. The respective change or adjustment of the set FAS torque can be linear, for example, or occur according to a predetermined function or dependency, or with a predetermined profile. For instance, the change or adjustment of the set FAS torque can occur at a predetermined rate or gradient, over a fixed time period, or depending on the extent or magnitude of the adjustment or change, and / or depending on the absolute value of the set FAS torque, and / or depending on the vehicle's speed, or the like.Depending on the design or implementation, for example, a particularly simple implementation and / or a particularly consistent behavior and / or a particularly safe behavior of the motor vehicle can be enabled and / or a period of time in which no free control of the longitudinal guidance by the driver assistance system is possible can be limited or set according to requirements. The present invention also relates to a vehicle system for a motor vehicle. The vehicle system according to the invention has an input interface for acquiring input data. This input data can, for example, specify or include the quantities or parameter values ​​mentioned in connection with the method according to the invention for determining or characterizing the respective driving situation and / or for determining the torque that would be applied in the respective driving situation in manual operation without longitudinal control interventions by the driver. Likewise, the input data can, for example, specify or include the target acceleration requested by the driver assistance system (FAS) – positive or negative – and / or a corresponding FAS torque for implementing the target acceleration.Similarly, the input data can, for example, indicate or signal whether and, if so, to what extent the driver intervenes in the longitudinal control, i.e., by operating or activating a corresponding brake and / or acceleration control element of the vehicle. Likewise, the input data can, for example, specify or include a derived or determined driver-requested acceleration and / or a corresponding driver-requested torque – positive or negative. The input data can also specify or include other or additional quantities or data. The vehicle system also includes a data processing unit for processing the input data, for example, to generate respective results and / or corresponding control signals. Furthermore, the vehicle system has an output interface for outputting corresponding results and / or control signals. The input interface and the output interface can be separate interfaces or combined or integrated in a common, bidirectional interface. The input interface and the output interface can each be implemented wholly or partially in hardware and / or in software. According to the invention, the vehicle system is configured to automatically execute the method according to the invention. The vehicle system, in particular its data processing unit, can, for example, comprise a processing unit, such as a microprocessor, microchip, microcontroller, or the like, and a computer-readable data storage device coupled thereto. This data storage device can then, for example, contain a corresponding operating or computer program that encodes or implements the process steps, measures, or sequences described in connection with the method according to the invention, or corresponding control instructions. This operating or computer program can then be executed by means of the processing unit to carry out the corresponding method or to effect its execution. The vehicle system according to the invention can, in particular, be the vehicle system mentioned in connection with the method according to the invention.The vehicle system according to the invention can be a separate system, for example, its own control unit, or it can comprise other components. Likewise, the vehicle system according to the invention can be combined or integrated, for example, with the driver assistance system and / or with a control system or control unit for brake or drive control. The present invention also relates to a motor vehicle that is equipped for both manual longitudinal control, i.e., control by a driver, and for at least assisted or at least partially automated longitudinal control by a driver assistance system. The motor vehicle according to the invention can therefore, in particular, have a corresponding driver assistance system. The motor vehicle according to the invention is equipped with the vehicle system according to the invention and can accordingly, in particular, be configured for the automatic execution or application of the method according to the invention. The motor vehicle according to the invention can therefore, in particular, be the motor vehicle mentioned in connection with the vehicle system according to the invention and / or in connection with the method according to the invention. Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. The drawing shows in: Fig. 1 a partial schematic representation of a motor vehicle that is equipped for manual and automated operation as well as torque-limited drive control; and Fig. 2 an exemplary schematic flow chart for a corresponding operating or control procedure. There are various driver assistance systems, including ACC and SRA. ACC is permitted to provide propulsion, thus generating positive torque, provided the set target or set speed is higher than the current actual speed and no vehicles ahead are obstructing it. SRA, at least except in near-standstill speed ranges, is typically designed primarily to adaptively control recuperation, increasing or decreasing it depending on the situation, and to only vary deceleration, thus generating only negative torque. A near-standstill speed range can, for example, be a vehicle's creep speed range, in which the vehicle can move without driver intervention, i.e., without manual operation of, for example, a brake and / or accelerator control, and without automated longitudinal control requests.Without automated longitudinal guidance intervention, it can or would move due to an active creep function or a creep moment specified – for example, as a foot point moment. The near-standstill range can, for example, be a speed range from 0 km / h to approximately 7 km / h or similar. If one wants to use the ACC's (Adaptive Cruise Control) chain of functions to implement a headlight range adjustment (SRA), this is initially not possible due to the potential resulting accelerations. More precisely, an SRA should not generate more torque than a driver would experience in a comparable driving situation without using the pedals. Similarly, there are situations in which ACC should not provide acceleration, for example, if the corresponding sensors are malfunctioning. Making a decision at the target acceleration level—whether a specific, for example, automatically requested, target acceleration will result in positive torque—is not straightforward due to disturbances such as wind and other environmental influences and / or surrounding conditions, such as inclines. These problems and challenges can, however, be addressed. Figure 1 shows a partial schematic representation of a motor vehicle 1, which can be controlled and longitudinally guided by a driver 2 in a manual operating mode and at least partially or fully automatically by a driver assistance system 3 in an automated operating mode. For manual driving, the motor vehicle 1 is shown here as an example with an accelerator pedal 4 and a brake pedal 5, which can be operated by the driver 2. When the accelerator pedal 4 and / or the brake pedal 5 is actuated, a corresponding signal can be sent to a drive system 6 of the motor vehicle 1 to implement the driver's command. Likewise, the driver assistance system 3 can send signals to the drive system 6 for automated longitudinal guidance.The drive system 6 can then control corresponding actuators, such as a hydraulic brake and / or an electric drive motor, in order to provide corresponding torques or to achieve corresponding positive or negative accelerations. The present application is to provide, or implement, a control mode in or by the vehicle 1 for the implementation or handling of a target acceleration. This mode limits or caps the torques required to regulate a target acceleration requested by the driver assistance system 3 to the torques that the driver 2 would receive in a driving situation corresponding to the current driving situation in manual mode without pedal operation. In manual mode, recuperation or a recuperation function and the driver 2 can be active, thus influencing the set torques. However, in manual mode, the driver assistance system 3 and any driver assistance functions that propel the vehicle 1 even outside the near-standstill speed range, and thus can generate positive torques that actively increase the speed of the vehicle 1, are not active. To offer this control mode, i.e., to implement the described functionality or behavior, the motor vehicle 1 also has a vehicle system 7, which is shown separately only as an example. The vehicle system 7 is represented here by an interface 8, a processor 9, and a computer-readable data storage device 10 coupled to it. For example, the vehicle system 7 can be connected, at least indirectly, via the interface 8 to the accelerator pedal 4 and the brake pedal 5, or corresponding sensors or signal transmitters, to the driver assistance system 3, and to the drive system 6. The vehicle system 7 can acquire respective data or signals via the interface 8.These can, for example, characterize the current driving situation and indicate or determine the driver's (2) input of the accelerator pedal (4) and brake pedal (5), as well as the positive or negative accelerations or corresponding torques requested by the driver assistance system (3). The vehicle system (7) can then process the acquired data or signals using the processor (9) and the data storage (10), generate corresponding control signals, and output them, for example, also via the interface (8), to the driver assistance system (3) and / or the drive system (6). To further illustrate the function of vehicle system 7, Fig. 2 shows an exemplary partial schematic flowchart 11. The procedure can be started in a process step S1. Here, for example, the driver assistance system 3 and the vehicle system 7, or – for example, by the active driver assistance system 3 – the aforementioned control mode can be activated. In a process step S2, the vehicle system 7 can determine the current driving situation and the moment or moments that would be provided in the current driving situation or one of these driving situations corresponding to the activity of the driving assistance system 3 and without intervention by the driver 2, in particular as a recuperation moment. In process step S3, the vehicle system 7 can cap, i.e., limit, the torque(s) required to regulate the target acceleration requested by the driver assistance system 3 to the torques determined in process step S2. Here, the corresponding limit can be activated – possibly regardless of whether the driver assistance system torque required to achieve the currently requested target acceleration is greater or less than the torque determined in process step S2. In process step S4, the vehicle system 7 can continuously check whether the current torque applied to achieve the target acceleration requested by the driver assistance system 3 (FAS) is greater than the limit. If so, in process step S5a, the currently applied FAS torque can be gradually reduced to the limit, i.e., to the value determined in process step S2. Otherwise, the vehicle system 7 can continuously check this in process step S5b. In this step, it can continuously check whether the limit is in effect or has been in effect, that is, whether the FAS torque that would have to be applied to achieve the target acceleration currently requested by the driver assistance system 3 has reached or is above the limit. If the gradual reduction is completed in process step S5a, or if it has been determined in process step S5b that the limit is or has been activated, i.e., has actually resulted in a smaller set FAS torque than would be the case without the limit, then the set FAS torque can be frozen at the limit value in process step S6. Likewise, a corresponding longitudinal control or acceleration controller of the driver assistance system 3 can be frozen in process step S6, or even as soon as it has been determined in process step S4 that the set FAS torque is at least equal to the limit. In process step S7, the vehicle system 7 can then continuously check whether a predefined end or termination condition is met. Such an end or termination condition could, for example, be checking whether the torque required to achieve the target acceleration currently requested by the driver assistance system 3 is below the limit, and / or whether the driver 2 has ended their longitudinal control intervention, i.e., their operation of the accelerator pedal 4 and / or the brake pedal 5, and / or whether the aforementioned control mode, in which the limitation of the set driver assistance system torque is provided, has ended, i.e., is deactivated. If the termination condition is met, the vehicle system 7 can, in a process step S8, gradually adjust the set FAS torque to a new target value, for example, a value necessary to realize the target FAS acceleration then requested by the driver assistance system 3. The set FAS moment can therefore be ramped, i.e., pulled to the respective intended level, for a correspondingly smooth activation or deactivation, for example when switching on or activating and when switching off or deactivating the aforementioned control mode, or when the limit initially applies and when the limit no longer applies or applies for the last time, for example linearly. Overall, the examples described show how a cap on a driver assistance moment can be implemented and applied to a driver request moment. Reference symbol list 1 Motor vehicle 2 Driver 3 Driver assistance system 4 Accelerator pedal 5 Brake pedal 6 Drive system 7 Vehicle system 8 Interface 9 Processor 10 Data storage 11 Flowchart S1 - S8 Procedure steps QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 10 2009 020 794 A1

[0003] EP 2 371 647 B1

[0004] WO 2017 / 084 977 A1

[0005]

Claims

Method (11) for controlling a motor vehicle (1) that is equipped for both manual longitudinal control by a driver (2) in a manual operating mode and for at least assisted longitudinal control by a driver assistance system (3) in an automated operating mode, wherein in a predetermined control mode, while the motor vehicle (1) is longitudinally controlled by the driver assistance system (3) in automated operating mode, the torque that would be actuated in the current driving situation without driving longitudinal control intervention by the driver assistance system (3) in manual operating mode without manual longitudinal control intervention by the driver (2) is automatically determined, and the actuating position of a driver assistance system (FAS) torque for regulating a target FAS acceleration requested by the driver assistance system (3) in the current driving situation is limited to the determined torque. Method (11) according to claim 1, characterized in that the determined moment comprises a recuperation moment. Method (11) according to one of the preceding claims, characterized in that the driving situation is characterized by the speed of the motor vehicle (1) and / or the acceleration of the motor vehicle (1) and / or the direction of travel of the motor vehicle (1) and / or the slope of the surface and / or a set recuperation level. Method (11) according to one of the preceding claims, characterized in that the actuating position of the FAS moment in the current driving situation is limited only in the direction of larger positive moments. Method (11) according to one of the preceding claims, characterized in that the limitation only takes place in the specified control mode and this control mode is set by the driver assistance system (3) or is set depending on a functional state of the driver assistance system (3), in particular in the event of a degradation of the driver assistance system (3) and / or a corresponding sensor system of the motor vehicle (1). Method (11) according to one of the preceding claims, characterized in that at the time when the limitation takes effect, a longitudinal guidance controller of the driver assistance system (3) and / or the actually set FAS torque is frozen. Method (11) according to claim 6, characterized in that the longitudinal control controller of the driver assistance system (3) and / or the actually set FAS torque remains frozen for as long as the torque necessary to regulate the FAS target acceleration corresponds at least to the determined torque and / or an actual longitudinal control intervention by the driver (2) continues. Method (11) according to one of the preceding claims, characterized in that - when, at the time the limitation takes effect, the set FAS torque is greater than the determined torque, the set FAS torque is gradually reduced to the determined torque, and / or - with deactivation of the specified control mode, the set FAS torque is gradually changed to a value to be set then. Vehicle system (7) for a motor vehicle (1), comprising an input interface (8) for acquiring input data, a data processing device (9, 10) for processing the input data and an output interface (8) for outputting resulting results and / or control signals, wherein the vehicle system (7) is configured to automatically execute the method (11) according to one of the preceding claims. Motor vehicle (1) which is equipped for manual longitudinal guidance by a driver (2) and for at least assisted longitudinal guidance by a driver assistance system (3) and which has a vehicle system (7) according to claim 9.

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