Method and vehicle system for vehicle control in a cooperative operating mode and changing driving situations, as well as a correspondingly equipped motor vehicle

Abstract

The invention relates to a method (11) for controlling a motor vehicle (1) that can be controlled manually and by a driver assistance system (3). In this method, when a non-zero target deceleration is requested by the driver assistance system (3) and a simultaneous manual actuation of a brake control element (5) is detected, the target deceleration requested by the driver assistance system (3) at the time of initial detection of this actuation, or a corresponding torque, is frozen. This frozen torque is then automatically reversed in its direction of action according to continuous monitoring of the driving situation, so that it continues to act as it did at the time of freezing, even in a changed driving situation. The invention also relates to a correspondingly configured vehicle system (8) and a motor vehicle (1) equipped therewith.

Description

[0001] 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.

[0002] Modern vehicles are increasingly equipped with functions and systems to improve user comfort or automate driving. This also increases complexity and, at least potentially, the susceptibility to errors or the risk of undesirable effects or behaviors in the respective vehicle. For example, unintentionally or erroneously excessive acceleration or deceleration can be problematic for both the driver and driver assistance systems. Approaches and rules already exist, for example, regarding functional safety or ensuring the correct control of hydraulic brakes or similar components. However, such implementations can become more difficult with increasing complexity, especially in cooperative operation where both the driver and a driver assistance system are actively involved in longitudinal control.

[0003] For example, DE 10 2015 012 377 A1 describes a method for adjusting brake pressures on pneumatically actuated wheel brakes of a motor vehicle. In normal operating mode, a brake pressure is set based on a driver's braking request. When an external braking request, independent of the driver's request, is received, a pressure control mode is used to apply a brake pressure to the respective wheel brakes, taking both the external and driver braking requests into account. The pressure control mode is terminated after the external braking request is withdrawn, based on a comparison of a value representing the driver's braking request with a predefined threshold. This ensures that, when the brake pressure is set in pressure control mode, continuous braking behavior is maintained after the external braking request is withdrawn.Furthermore, it is described there that the external braking request and the driver's braking request can be additively superimposed if they occur simultaneously. Alternatively, a maximum value can also be calculated from the target braking values ​​already requested internally by a braking system and an external target braking value, whereby the external braking request is only set if it is higher than the internal braking request.

[0004] German patent DE 602 18 294 T2 describes a driver assistance system for a motor vehicle with an electrically controlled brake actuation device. Among other things, it describes that a control unit, which monitors the execution of functions for longitudinal control of the motor vehicle, is connected to sensors assigned to a brake pedal and an accelerator pedal, respectively. Each actuation of the brake pedal then deactivates the corresponding longitudinal control function, thereby reactivating the driver's control of the motor vehicle. Conversely, pressing the accelerator pedal allows a set reference speed to be exceeded without the need to deactivate the corresponding longitudinal control function.

[0005] However, existing approaches can present problems. For example, if a driver assistance function for longitudinal control of a vehicle generates a negative torque, i.e., a braking torque, and the driver assistance function is deactivated when the driver presses the brake pedal, the driver is initially decelerated. This means that the driver presses the brake pedal, but the initial deceleration of the vehicle may be reduced, which can contradict the driver's actual intention when pressing the brake pedal. If, on the other hand, the driver assistance function remains active when the driver presses the brake pedal and an additive combination of the corresponding braking effects or torques is provided, then two controllers would be active simultaneously: the driver and the driver assistance function.This would be virtually impossible for the driver to control, meaning they could not precisely and reliably set a specific desired deceleration because they would constantly have to work against a changing input from the driver assistance system. Even if, for example, the braking torque generated by the driver assistance system were initially maintained and only the controlling influence of the system were deactivated, undesirable effects could occur. For instance, a rapid reduction in braking torque could lead to disruptive noise, and in certain situations, the torque initially intended as braking could suddenly act as an accelerating force. These effects can also be undesirable, as they could, for example, at least lead to driver uncertainty. Therefore, there is a need for further improvements in this area.

[0006] The object of the invention is to enable a driver of a motor vehicle to achieve precise and comfortable longitudinal guidance or longitudinal guidance control of the motor vehicle in a particularly robust and reliable manner, even when an active driving assistance system is in use.

[0007] 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.

[0008] The method according to the invention can be used for or in the control of a motor vehicle that is equipped 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. In particular, a braking system or a braking and drive system of the motor vehicle can be controlled. The motor vehicle or its braking system can, for example, include at least one brake actuator for generating a braking torque, i.e., a decelerating or negative torque. Such a brake actuator can, in particular, be or comprise a hydraulic friction brake. Likewise, corresponding braking torques or negative drive torques can be generated by means of an electric drive motor. Such an electric drive motor can also generate accelerating, i.e., positive torques, and thus be part of the drive system of the motor vehicle.

[0009] In the method according to the invention, a driving situation in which the respective motor vehicle, in which the method is applied, is continuously monitored. The driving situation can be characterized, for example, by an operating state of the motor vehicle or by a behavior or state of the motor vehicle relative to its environment. A driving situation can thus include, for example, the current direction of travel and / or speed and / or a selected gear or selector lever position and / or operating actions of a driver or vehicle occupants and / or control measures of at least one driver assistance system of the motor vehicle and / or an incline or decline of the road surface being driven on and / or the like. Likewise, continuous monitoring is performed for target decelerations requested by the driver assistance system.The corresponding moments and manual actuations of a brake control element of the respective vehicle are carried out. The fact that the driver assistance system requests a specific target deceleration can mean, for example, that it calculates a specific target deceleration 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 a corresponding actuator to implement the request, i.e., the requested target deceleration, by setting, i.e., generating a corresponding moment, or to a corresponding control unit, in this case, in particular, to a brake actuator or a brake and / or drive control unit of the vehicle.

[0010] A brake control element can be, in particular, a brake pedal. It is therefore possible to monitor whether the driver of the vehicle is manually operating the brake control element. Monitoring can also be carried out for the actuation of an acceleration control element, in particular an accelerator or drive pedal, and, if necessary, the resulting driver-initiated acceleration torque can be taken into account. A corresponding driver-initiated braking torque can be determined from each actuation of the brake control element. This can be composed of an actual driver contribution, which is zero without actuation of the brake control element and increases with increasing actuation of the brake control element, and, if necessary, a predefined offset or foot point torque.Such an offset or baseline torque can, for example, be or include a predetermined creep torque or recuperation torque, which can be different from zero even without actuation of the brake control element, i.e., at its baseline or in its zero or rest position. For example, a driver-request torque can result from a balance between the driver-requested acceleration torque and the driver-requested braking torque. Without actuation of the acceleration control element, the driver-requested torque can therefore correspond to the driver-requested braking torque.

[0011] In the method according to the invention, it is detected when, during a target deceleration requested by the driver assistance system, i.e., during a deceleration of the vehicle caused by the driver assistance system, or when the driver assistance system or a speed controller of the driver assistance system has requested or set a target deceleration other than zero or a corresponding braking torque, i.e., simultaneously with a corresponding activity of the driver assistance system, the brake control element is manually actuated by the driver. Upon such actuation of the brake control element, or upon its detection, an actuator-set torque corresponding to the target deceleration requested by the driver assistance system (i.e., a current target deceleration of the driver assistance system), referred to here as the driver assistance torque, is automatically frozen, that is, its value is fixed.The frozen FAS torque is exempt from further regulation by the driver assistance system. It can then be set or kept constant until further notice, or controlled independently of the driver assistance system's controller in a predefined manner. Accordingly, the driver assistance system can no longer actively intervene in the longitudinal guidance of the vehicle. The frozen FAS torque can thus be effectively defined as a new or temporary foot point torque for the driver or the brake control, or, together with the offset or foot point torque that is predefined by default without brake control activation, it can form a temporary foot point torque used during the current brake control activation or until the FAS torque is reduced.The FAS moment can be determined or managed, i.e., set or controlled, for example by the driver assistance system itself, or by the brake and drive system, or an actuator control unit of the motor vehicle, or by a vehicle system set up to carry out the method according to the invention.

[0012] While the FAS torque is frozen, the driver can adjust the braking force by varying the application of the brake lever, i.e., by manually applying the brakes. This allows for any deceleration greater than the FAS target deceleration at the moment of freezing, meaning any braking torque that is more negative than the frozen FAS torque. Because the FAS torque, and therefore a control element of the driver assistance system, is frozen and cannot actively intervene in the longitudinal control (i.e., the actual deceleration of the vehicle), the driver is then the sole active controller, acting as the variable or influencing factor for the longitudinal control and actual deceleration. This enables the driver to precisely and consistently set a specific actual deceleration of the vehicle by applying the brake lever.At the same time, the present invention prevents the actual deceleration of the vehicle from initially decreasing when the driver operates the brake control and the driver assistance system is simultaneously active, as would be the case, for example, if the driver assistance system or its influence on longitudinal guidance were instantly and completely deactivated upon activation of the brake control. This already results in improved safety and comfort.

[0013] According to the invention, if a driving situation that has changed compared to the time of the initial freezing of the FAS torque is detected, and the frozen FAS torque no longer has a decelerating effect in the new or changed driving situation (i.e., it no longer points or acts in the direction of a standstill or against the current direction of travel of the motor vehicle), but this was the case at the time of the initial freezing of the FAS torque (i.e., in the immediately preceding driving situation in which the FAS torque was initially frozen), the sign, i.e., the direction of action of the frozen FAS torque, is reversed so that it also has a decelerating effect in the new, changed driving situation.

[0014] It is therefore possible to continuously check, or at least when a change in the driving situation is detected, whether the frozen FAS torque is currently having a decelerating effect, i.e., in the direction of stopping or bringing the vehicle to a standstill. If this is not the case, it can be checked whether the frozen FAS torque was having a decelerating effect at the time it was frozen. This can also be checked beforehand. In particular, this can be saved each time the FAS torque is initially frozen. For verification purposes, a corresponding saved value can then be queried, for example.

[0015] Based on these results, it can then be determined whether the frozen FAS torque needs to be adjusted to maintain its braking effect in the new, changed driving situation. If so, the frozen FAS torque is adjusted accordingly. A frozen FAS torque can also be adjusted multiple times if the driving situation changes several times.

[0016] The present invention takes into account that even in near-standstill speed ranges, for example, at vehicle speeds of just a few km / h, significant torques may be necessary to achieve a target deceleration requested by the driver assistance system. These torques can then be applied, and the driver can only initially activate the brake control within this near-standstill speed range. For example, to achieve a particularly large, i.e., strong, target deceleration by the driver assistance system until the vehicle comes to a standstill, a correspondingly large torque from the system can be applied if this is the only way to avoid a collision. Similarly, a relatively large torque from the system can be applied if the vehicle needs to be slowed down or brought to a standstill on an incline or decline.

[0017] A near-standstill range or speed range can, for example, be a creep speed range of the respective vehicle, in which the vehicle can or would move without driver intervention, i.e., without manual operation of a brake and / or acceleration control element, and without a longitudinal guidance request from a driver assistance system, due to an active creep function or a creep torque specified – for example, as a foot-point torque. The near-standstill range can, for example, be a speed range from 0 km / h to approximately 7 km / h or similar.

[0018] While a frozen FAS torque can generally be reduced, this should not be done too quickly. This can lead to undesirable effects, such as disruptive noises during a rapid and significant pressure drop in the braking system, excessive stress on vehicle components, or a change in the vehicle's behavior or condition that is too rapid and therefore potentially confusing or difficult for the driver to control. If the reduction of a frozen FAS torque were too slow, it could continue beyond the point where the vehicle comes to a complete stop or even beyond a change in the driving situation. This, in turn, could result in a delayed response from the vehicle or behavior that is no longer appropriate for the changed driving situation.For example, the direction of travel, i.e., the direction of movement of the vehicle relative to its surroundings, might have reversed in the changed driving situation. A FAS moment that was frozen before this change in the driving situation would then have had a decelerating effect before the change, but would have an accelerating effect afterward. This could lead to a sudden change in the vehicle's behavior, which could be irritating, surprising, and / or difficult for the driver to control.

[0019] These problems can be solved by the present invention. By reversing the direction of action of a frozen torque when the driving situation changes accordingly, a frozen FAS torque can act consistently, regardless of the direction of travel or even across changes in the vehicle's direction of travel, thus causing consistent vehicle behavior. At the same time, undesirable effects that would result from a very rapid dissipation of a frozen FAS torque are avoided. Therefore, overall, safe, intuitively understandable, and easily controllable vehicle behavior can be achieved in corresponding situations and during changes in driving conditions.

[0020] In one possible embodiment of the present invention, the frozen FAS torque is automatically reduced gradually, i.e., not instantaneously or abruptly, and in particular continuously. In a further development of the present invention, this reduction can be achieved, in particular, with a predetermined maximum gradient, i.e., with a corresponding predetermined maximum reduction rate or rate. For example, the frozen FAS torque can be reduced completely, i.e., down to zero, or to a new setpoint for the changed driving situation determined by the driver assistance system or a feedforward control of the driver assistance system. This can occur over one or more changes in the direction of action. The frozen FAS torque can be reduced in a predetermined manner, i.e., linearly, according to a predetermined function, or in a predetermined sequence.

[0021] Meanwhile, the driver assistance system's control influence on longitudinal guidance may be suspended. For example, the driver assistance system's controller or speed controller may be frozen, continuously reset, or a specific output value from the controller may be forced to achieve the intended reduction. Similarly, during the reduction of the driver assistance system's torque, control requests from the driver assistance system or corresponding signals from the controller may be blocked, ignored, or discarded, for example, by the vehicle's braking and drive systems (mentioned elsewhere) or by the vehicle's systems.

[0022] Because the reduction of the FAS torque occurs gradually or with a limited gradient, the driver can comfortably and safely compensate for any changes in the vehicle's behavior, for example, by gradually increasing or decreasing the pressure applied to the brake and / or accelerator controls depending on the driving situation. This would not be possible if, for instance, the FAS torque were to drop abruptly upon initial application of the brake controls, upon reaching a standstill, or upon recognizing the change in the driving situation. Furthermore, the gradual reduction of the FAS torque proposed here avoids disruptive noises or acoustic disturbances that could occur with a sudden reduction of the entire frozen FAS torque, which could, for example, impair comfort or unsettle the driver.

[0023] Depending on requirements or needs, the reduction of the FAS torque can be achieved with a fixed reduction rate or a corresponding gradient, for example, the specified maximum gradient. This allows the driver to consistently compensate for the reduction in different situations, even with varying initial frozen FAS torque values. The reduction rate, i.e., the gradient of the FAS torque magnitude, can also be dynamically determined automatically, for example, based on the vehicle's speed and / or the magnitude of the FAS torque at the time of initial freezing, or similar factors. This can be accomplished using a corresponding calculation algorithm, a characteristic map, a mapping table, or similar parameters.This allows for the particularly comfortable dissipation of relatively small, initially frozen FAS moments, while ensuring that relatively large, initially frozen FAS moments are dissipated neither too quickly nor too slowly or for too long. This allows for an excellent compromise between comfort, safety, and ease of control and handling of the vehicle for the driver.

[0024] In a further possible embodiment of the present invention, the FAS torque is frozen only in an additive operating mode, in which both the target deceleration requested by a controller of the driver assistance system and a driver-requested deceleration indicated by actuation of the brake control element, or corresponding torques, are additively combined to form an actually set deceleration or a corresponding actual or total torque. In such an additive operating mode, the FAS torque and the driver-requested torque resulting from or determined by actuation of at least the brake control element or the acceleration control element can thus be added together. The resulting sum of these torques can then be set as the total torque or combined with other contributing torques to form the total torque to be set.In additive operating mode, for example, when the driver assistance system and the driver are simultaneously active for longitudinal control of the vehicle, there is no blending between the corresponding requirements of the driver assistance system and the driver, and there is no partial consideration of the FAS target deceleration and / or the driver's desired deceleration.

[0025] The additive operating mode can be requested by the driver assistance system, or detected or set based on a corresponding signal from the driver assistance system. Similarly, the additive operating mode can be set or activated manually by the driver, or in some other way.

[0026] Outside of additive operating mode, a different operating mode can be used, i.e., a different, non-additive combination of the FAS target deceleration and the driver's desired deceleration or corresponding torques. In this mode, for example, the FAS target deceleration or the sum of the FAS target deceleration and the driver's desired deceleration or corresponding torques can be gradually blended to the pure driver's desired deceleration or torque, or a maximum selection can be made so that only the greater deceleration or only the torque with the larger absolute value is used or considered for the longitudinal guidance of the vehicle.

[0027] The additive operating mode can offer certain advantages over other operating modes, at least in specific situations. For example, it can prevent the driver from having to bridge or traverse a period of free play when operating the brake control before their action has an effect on the vehicle's longitudinal control. In other operating modes, conflicts or competing control influences between the driver's input and those of the driver assistance system can be avoided in other ways, thus eliminating the need, for instance, to freeze the driver assistance system torque when the brake control is operated by the driver. Therefore, by applying the present invention only in the additive operating mode, individually optimized vehicle control can be implemented for different situations or requirements.

[0028] In a further possible embodiment of the present invention, the direction of travel of the motor vehicle is also monitored, at least as a component or characterization of the driving situation. In other words, the direction of travel of the motor vehicle relative to its immediate surroundings can be considered or evaluated to recognize or determine the driving situation or to detect a change in the driving situation. For example, the direction of travel can be determined or monitored based on a sensor-detected wheel rotation direction. The direction of travel can be a useful factor for characterizing the driving situation and a particularly influential or relevant factor with regard to the effect of a frozen FAS moment on the behavior of the motor vehicle. Thus, by considering the direction of travel as proposed here, the present invention can be implemented, i.e., applied, particularly effectively.come into play.

[0029] In a further possible embodiment of the present invention, at least one selector lever position, i.e., a selected gear, is also monitored to monitor the driving situation, i.e., as part of or to characterize the driving situation. In other words, to determine or detect the driving situation or a change in the driving situation, it is possible, for example, to monitor, consider, or evaluate whether and, if so, how the driver operates or actuates a selector lever of the motor vehicle. For this purpose, for example, a suitable sensor can be used to directly detect the selector lever position, or a corresponding signal or state of a transmission control unit can be evaluated, or the like.

[0030] The gear selector position, i.e., the selected gear or the gear requested by actuating the gear selector, can have a significant influence on the vehicle's driving situation. In particular, an actuation of the gear selector or a change in its position can allow for the rapid or early detection of a current or impending change in the driving situation. For example, a change in the gear selector position may indicate an intended reversal of the vehicle's direction of travel, even before the vehicle has actually moved. This allows sufficient time to reverse the direction of action of the frozen FAS torque, thus enabling a particularly comfortable, reliable, and stress-free reversal.

[0031] 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, include a positive or negative target acceleration from the driver assistance system (FAS), in particular a requested target deceleration, and / or a corresponding FAS torque for implementing the target acceleration, on the one hand, and an actuation signal that can indicate the current actuation position of the brake control element or the acceleration control element, and / or a driver-requested deceleration or a corresponding driver-requested torque derived therefrom.Furthermore, the input data may include, for example, the current direction of travel of the motor vehicle and / or the current position of a selector lever of the motor vehicle and / or the current speed of the motor vehicle and / or, depending on requirements or implementation, further and / or other parameter values, in particular to characterize a particular driving situation of the motor vehicle.

[0032] 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 for the automatic execution of the method according to the invention.

[0033] 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.

[0034] 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.

[0035] 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 on their own, without departing from the scope of the invention.

[0036] The drawing shows in: Fig. 1 a partial schematic representation of a motor vehicle designed for manual and automated operation as well as for automatic handling of braking torques produced by a driver assistance system in an additive operating mode and different driving situations; and Fig. 2. An exemplary schematic flowchart for a corresponding procedure.

[0037] If a vehicle can simultaneously operate an automatic longitudinal control function alongside manual longitudinal control, various possibilities exist for corresponding cooperation between human and machine, or between manual and at least assisted or at least partially automated driving. One example is additive behavior, i.e., an additive operating mode in which torques generated by the driver assistance function and torques generated by manual controls are additively incorporated into the longitudinal control. With the introduction of such an additive operating or cooperative mode in a vehicle, torques applied via a brake control element can be added to torques generated by driver assistance functions. To ensure well-controlled and safe vehicle handling during manual additive braking in at least assisted or at least partially automated driving mode, a corresponding additive braking system is required.To ensure consistent deceleration behavior, certain additional measures can be useful. For example, to avoid a conflict between two controllers or two simultaneously and potentially opposing influences, the torque generated by the driver assistance function (FAS torque) can be frozen, meaning it is initially fixed during a manual longitudinal control intervention. Such frozen FAS torques can then be reduced according to various criteria or specifications, such as when the brake control is released, the vehicle speed, a specific time period, a predetermined maximum gradient, or at least a limited reduction based on these factors.

[0038] However, if a driver only begins to brake shortly before coming to a standstill or in a near-standstill speed range, in accordance with the deceleration caused by the driver assistance function, a driver assistance system (FAS) moment may still be frozen or still in the process of dissipating, correspondingly near or at a standstill.

[0039] If the driving situation then changes, the frozen FAS moment can have the wrong effect. However, this can be avoided by taking further measures.

[0040] This shows Fig. 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 by a driver assistance system 3 in an automated operating mode. For manual driving, the motor vehicle 1 is shown here as an example having an accelerator pedal 4, a brake pedal 5, and a gear selector 6, which can be operated by the driver 2. When the accelerator pedal 4 and / or the brake pedal 5 and / or the gear selector 6 is actuated, a corresponding signal can be sent to a brake and drive system 7 of the motor vehicle 1 to implement a corresponding driver request. Likewise, the driver assistance system 3 can send signals to the brake and drive system 7 for automated longitudinal guidance. The brake and drive system 7 can then control corresponding actuators to apply the appropriate torques.to achieve corresponding positive or negative accelerations in the appropriate direction.

[0041] In an example situation, driver 2 may have selected drive mode "R" using selector lever 6, and vehicle 1 may be moving in reverse. Driver 2 can then select drive mode "D" using selector lever 6. This indicates that vehicle 1 should move forward. The driver assistance system 3 can then request a negative target acceleration, i.e., a target deceleration. This can be achieved by a corresponding decelerating force from the driver assistance system, in this case and at this time, acting forward in the longitudinal direction of the vehicle. To accelerate the stop for the intended change of direction, driver 2 can then depress the brake pedal 5. This deceleration of the brake pedal 5 freezes the forward-acting force from the driver assistance system.If the vehicle 1 now comes to a standstill and starts moving forward before the frozen FAS moment has dissipated, it would no longer have a decelerating effect, unlike at the time of freezing, but on the contrary, an accelerating effect.

[0042] To prevent this, the motor vehicle 1 also has a vehicle system 8. The vehicle system 8 is shown separately here only as an example and is schematically represented by an interface 9, a processor 10, and a computer-readable data storage device 11 coupled to it. Via the interface 9, the vehicle system 8 can be connected, at least indirectly, to the accelerator pedal 4 and the brake pedal 5 or corresponding sensors or signal transmitters, to the selector lever 6, to the driver assistance system 3, and to the braking and drive system 7 in order to receive and / or send respective data and / or signals. Likewise, the vehicle system 8 can also detect the current direction of travel and the current speed of the motor vehicle 1, for example, also via the interface 9.

[0043] The vehicle system 8 is now configured to continuously monitor the current driving situation of the motor vehicle 1 in order to detect changes in the driving situation. In particular, the vehicle system 8 can detect a changed driving situation if the direction of movement or travel of the motor vehicle 1 reverses or if the selector lever 6 is moved to a position corresponding to a changed direction of travel. Furthermore, the vehicle system 8 is configured to freeze any braking torques or decelerations caused or requested by the driver assistance system 3, i.e., by one or more driver assistance functions, at the beginning of any detected braking action by the driver 2, i.e., upon detection of brake pedal 5 activation, the current driver assistance system torque, i.e., the respective driver assistance system torque, and, if necessary, to adjust its direction of action relative to the direction of movement or travel in the event of a detected change in the driving situation.The direction of travel, i.e., the vectorial velocity of the vehicle 1, is reversed so that an initially decelerating FAS moment continues to have a decelerating effect even after a change in the driving situation. For this purpose, the vehicle system 8 can, for example, control the driver assistance system 3 and / or the braking and drive system 7 accordingly.

[0044] To further illustrate this, shows Fig. 2. An exemplary schematic flowchart 12 for a corresponding procedure for operating or controlling the motor vehicle 1. The procedure can be started in a procedure step S1. Here, for example, the motor vehicle 1, the driver assistance system 3, and the vehicle system 8 can be commissioned, and / or the additive operating mode can be requested or activated. With the commissioning of the vehicle system 8, it can also, in particular, start the continuous monitoring of the driving situation.

[0045] In process step S2, the vehicle system 8 can continuously check whether a target deceleration requested by the driver assistance system 3 and the brake pedal 5 actuated by the driver 2 are present simultaneously. If this is not the case, i.e., if only a target deceleration requested by the driver assistance system 3 or the brake pedal 5 is actuated, then in process step S3 the respective corresponding request of the driver assistance system 3 or the driver 2 can be implemented.

[0046] If simultaneity is detected in process step S2, the resulting FAS torque can be frozen in process step S4, or its freezing can be initiated by the vehicle system 8. Furthermore, the vehicle system 8 can determine and store the current direction of action of the FAS torque.

[0047] In a process step S5, for example the vehicle system 8 can continuously check whether, according to the monitoring of the driving situation, i.e. also in the case of detected changed framework conditions, the frozen FAS moment has a delaying effect, i.e. in the direction of the standstill of the vehicle 1, just as at the time of the initial freezing, or whether a corresponding continuous check or monitoring can be started.

[0048] If it is detected that at a given time the FAS torque no longer has a decelerating effect, unlike at the time it was frozen, meaning that the FAS torque must be reversed due to the changed conditions (i.e., the current altered driving situation) in order to continue having a decelerating effect, the FAS torque, or rather its direction of action, is reversed accordingly in a process step S6. The magnitude of the FAS torque can remain unchanged.

[0049] The frozen FAS moment can be gradually reduced in a process step S7, i.e. according to predefined rules or conditions, regardless of its current direction of action.

[0050] After the FAS moment has completely dissipated, the vehicle system 8 can, for example, release the speed or longitudinal control via the driver assistance system 3 again - for example, at least or only if the driver 2 does not or no longer operates the brake pedal 5.

[0051] Overall, the examples described show how frozen moments can be rotated in an additive operating mode to enable robust and reliable precise and comfortable manual vehicle control. Reference symbol list 1 motor vehicle 2 drivers 3 Driver assistance systems 4 Accelerator pedal 5 Brake pedal 6 Selector lever 7 Drive system 8 Vehicle system 9 Interface 10 processor 11 Data storage 12. Schedule S1 - S7 process steps QUOTES INCLUDED IN THE DESCRIPTION

[0000] 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

[0000] DE 10 2015 012 377 A1

[0003] DE 602 18 294 T2

[0004]

Claims

Method (12) for controlling a motor vehicle (1) that is equipped for manual longitudinal control by a driver (2) and for at least assisted longitudinal control by a driver assistance system (3), wherein: - continuous monitoring of a driving situation is carried out, as well as on target decelerations requested by the driver assistance system (3) and on manual actuations of a brake control element of the motor vehicle; - when the brake control element (5) is actuated by the driver (2) during a target deceleration requested by the driver assistance system (3), an actuator-set FAS torque corresponding to the target deceleration requested by the driver assistance system (3) is frozen; - when a driving situation that has changed compared to the time the FAS torque was frozen is detected and the frozen FAS torque no longer has a decelerating effect, but this was the case at the time the FAS torque was frozen,The direction of action of the FAS torque is reversed, so that it also has a decelerating effect in the changed driving situation. Method (12) according to claim 1, characterized in that the frozen FAS moment is automatically reduced gradually. Method (12) according to claim 2, characterized in that the reduction of the FAS moment is carried out with at most a predetermined maximum gradient. Method (12) according to one of the preceding claims, characterized in that the FAS moment is frozen only in an additive operating mode in which both the target deceleration requested by a controller of the driver assistance system (3) and a driver-requested deceleration indicated by actuation of the brake control element (5) are additively combined to form an actually set actual deceleration. Method (12) according to one of the preceding claims, characterized in that the direction of travel of the motor vehicle is monitored to monitor the driving situation. Method (12) according to one of the preceding claims, characterized in that a selector lever position (6) is monitored to monitor the driving situation. Vehicle system (8) for a motor vehicle (1), comprising an input interface (9) for acquiring input data, a data processing device (10, 11) for processing the input data and an output interface (9) for outputting resulting results and / or control signals, wherein the vehicle system (7) is configured to automatically execute the method (12) 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 (8) according to claim 7.

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