Method and assistance system for the longitudinal guidance of a vehicle in the event of manual and automatic torque requests, and correspondingly configured motor vehicle

Abstract

The invention relates to a method and an assistance system (10) for controlling a drive system (2) of a motor vehicle (1) and to a corresponding motor vehicle (1). In the method, it is determined whether an assistance target torque (15) requested by a driving assistance function (9) decelerates more strongly than a specified decelerating offset torque (16) which results as the driver's desired torque (17) without an actuation of an accelerator pedal (7). If this is the case, the driver's desired torque (17) is reduced, at least when the accelerator pedal (7) is being actuated, by the difference between the assistance target torque (15) and the offset torque (16) in order to determine a total target torque (14). The drive system (2) is then actuated in order to set the total target torque (14).

Description

[0001] Method and assistance system for vehicle longitudinal guidance in the case of manual and automatic torque requirements and correspondingly equipped motor vehicle

[0002] The present invention lies in the field of automotive engineering and relates to a method and an assistance system for controlling a drive system of a motor vehicle. The invention also relates to a correspondingly configured motor vehicle.

[0003] Motor vehicles today are increasingly being equipped with functions and systems for automating vehicle control or driving tasks. However, these vehicles, at least so far, can still be controlled manually by a driver. This can lead to simultaneous control inputs or control requests from a driver assistance system for automated vehicle control and from the driver, which can overlap or even contradict each other. This, in turn, can lead to unexpected or uncomfortable reactions or behaviors from the vehicle. Therefore, there is a need for solutions to control such vehicles comfortably and consistently, or to enable or improve cooperation, i.e., the interaction between manual and automated vehicle control.

[0004] For example, DE 102020 126 680 A1 describes a vehicle guidance system for providing a driving function for the automated longitudinal guidance of a vehicle at a signaling unit. The vehicle guidance system is configured to detect that an accelerator pedal is actuated during operation of the driving function and to determine actuation information related to this actuation and / or a resulting reaction of the vehicle. The vehicle guidance system can then adapt the operation of the driving function depending on the actuation function, in particular to continue or abort it.

[0005] DE 10 2016 202 460 A1 describes an assistance system for assisting the driver of a motor vehicle in positioning the vehicle at a specified target position. The assistance system can repeatedly determine position information regarding the relative position of the vehicle to the target position. Furthermore, the assistance system can influence the manual longitudinal guidance of the vehicle by counteracting the vehicle's movement, at least for certain relative positions, depending on the respective position information, with the goal of bringing the vehicle to a stop essentially at the target position.

[0006] The object of the present invention is to enable efficient and comfortable manual guidance of a motor vehicle which is also equipped for automated longitudinal guidance.

[0007] This problem is solved by the subject matter of the main claim and the subsidiary claims or the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented 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 any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.

[0008] The method according to the invention can be used to control a drive system of a motor vehicle, wherein the motor vehicle or the drive system comprises an electric drive motor, i.e., an electric machine for driving the motor vehicle, in particular also for recuperating energy in generator mode. The method according to the invention comprises several method steps that can be executed automatically, continuously or regularly, at least as long as the method is to be executed, i.e., in corresponding situations.

[0009] In the method according to the invention, the actuation position of an accelerator pedal of the motor vehicle is monitored continuously or in each situation or under each condition for which automatic execution of the method is specified. Thus, for example, the position or angle of the accelerator pedal can be measured using a corresponding sensor. A corresponding driver command torque is then determined in each case or continuously.

[0010] This driver request torque is made up of a predefined negative, i.e. decelerating, offset torque that is active even without manual operation of the accelerator pedal by the driver of the vehicle, for example, which flows into a torque balance or into the determination of a current total target torque, and an accelerator pedal torque that depends on the actuation position of the accelerator pedal. The offset torque can, for example, be constant. This offset torque can, for example, be used to achieve recuperation without actuation of the accelerator pedal and without automatically requested drive torque. In contrast to the offset torque, the accelerator pedal torque can be influenced manually and directly by the driver by actuating or changing the actuation position of the accelerator pedal. The accelerator pedal torque can be zero without actuation of the accelerator pedal and increase with increasing actuation of the accelerator pedal, for example linearly or according to a predefined characteristic curve.

[0011] Furthermore, the method according to the invention monitors for a deceleration torque requested by a driver assistance function for at least assisted or at least partially automated longitudinal guidance of the motor vehicle or by a corresponding driver assistance system of the motor vehicle, which can be referred to here as the assistance target torque or ADAS torque (ADAS: driver assistance system). For this purpose, for example, a corresponding data signal can be detected, a corresponding parameter value can be read from a data memory, or the like.

[0012] If the assistance target torque is more negative, i.e., more decelerating, than the offset torque or than a total driver request torque, which results from the balance sum of the offset torque, the accelerator pedal torque, and a brake pedal torque, according to the invention, the corresponding driver request torque is always reduced, or at least when the accelerator pedal is then actuated by the driver of the motor vehicle, by the difference between the assistance target torque and the offset torque. In this way, the total target torque to be set, i.e., generated, is determined. Analogous to the accelerator pedal torque, the brake pedal torque can be a decelerating torque set or requested directly by the driver by actuating a brake pedal of the motor vehicle, which is therefore dependent on the current actuation position of the brake pedal.

[0013] Furthermore, according to the method according to the invention, the drive system is then controlled or regulated to set or generate the respectively determined total target torque.

[0014] In previous approaches, or in vehicles with an internal combustion engine, decelerating assistance target torques were typically implemented directly by means of a braking system, i.e., a friction brake of the respective vehicle. When the driver simultaneously depressed the accelerator pedal, this could create a tension state between the drive and braking system, which could slow the driver down to a certain extent. However, the use of an electric drive motor opens up the possibility of also providing decelerating torques using the electric drive motor itself. This eliminates the need to use the friction brake, which enables particularly fast and smooth, or jerk-free, vehicle handling and can reduce wear and the generation of brake dust.However, this would mean that the braking of the driver, which would otherwise be achieved by means of the friction brake, for example in the event of a detected risk of collision or the like, would no longer be possible or at least no longer be possible in the same way, or at least the driver could experience a significantly different accelerator pedal feel.

[0015] These problems can be avoided or mitigated by the present invention. By applying the present invention, the total target torque reaches a value at which the motor vehicle starts moving later than the driver is used to, possibly from purely manual driving mode, i.e. without a requested decelerating assistance target torque. This gives the driver a similar driving feel or accelerator pedal feel of the tensioning of the drive and brake actuators as in earlier vehicles, without the brake system having to work against the accelerator pedal torque. In this case, torques requested by the driver via the accelerator pedal can be offset or balanced against torques requested by the driving assistance function or the corresponding driving assistance system before they are output to the drive system or a corresponding actuator for implementation. This allows the driver to be shown the desired torque regardless of the actuator from which the requested or requested torque is derived.A similar feeling can be conveyed when the torque to be set is implemented. Corresponding actuators in this sense can be, for example, the electric drive motor or a braking system or a brake actuator for actuating a friction brake.

[0016] Overall, the present invention therefore enables efficient, flexible, and comfortable operation of the motor vehicle. Furthermore, the present invention can benefit traffic safety and vehicle driving. This is the case because, in situations where a requested decelerating assistance target torque is requested, the driver experiences a different feeling or behavior when attempting to override it by depressing the accelerator pedal than in situations in which the accelerator pedal is depressed and the driver assistance function does not request a decelerating assistance target torque. This different behavior can alert the driver that there is, for example, an obstacle in front of the motor vehicle or another reason for the motor vehicle to stop, or generally to exercise caution.Especially because of the often very rapid acceleration of electrically powered vehicles, which is still unfamiliar to many drivers today, this can potentially prevent or mitigate collisions or accidents.

[0017] The present invention also relates to an assistance system for a motor vehicle. The assistance system according to the invention has an input interface for acquiring pedal data corresponding to an operating position of an accelerator pedal of the respective motor vehicle equipped with the assistance system, and driver assistance function data. The pedal data can, for example, indicate a respective current actuation position of the accelerator pedal or the corresponding accelerator pedal torque. The driver assistance function data indicates the respective desired assistance torque, in particular the deceleration torque, requested by the driver assistance function of the respective motor vehicle for at least assisted or at least partially automated longitudinal guidance of the motor vehicle.The assistance system according to the invention further comprises a data processing device for processing the acquired data and for determining a corresponding total target torque, as well as for generating a corresponding control signal. Furthermore, the assistance system has an output interface for outputting the control signals. Via this interface, the assistance system can output control signals, for example, directly to the drive system or an actuator of the drive system of the respective motor vehicle or to an intermediate control unit.

[0018] The output interface and the input interface can be separate interfaces or integrated or combined into a common bidirectional interface. The interfaces can be implemented entirely or partially in hardware and / or software.

[0019] The assistance system according to the invention is configured to execute, in particular automatically, the method according to the invention. For this purpose, the data processing device can comprise, for example, a processing device, such as a microprocessor, microchip, microcontroller, or the like, and a computer-readable data memory coupled thereto. A corresponding operating or computer program can be stored in this data memory, which codes or implements the method 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 executable by means of the processing device in order to execute the corresponding method or to effect its execution.

[0020] In one possible embodiment of the present invention, the assistance system is configured to apply the method, in particular only when the initial actuation of the accelerator pedal occurs when the motor vehicle is stationary or from a stationary state after the driver assistance function has automatically stopped the motor vehicle, i.e., brought it to a standstill, based on a predetermined, i.e., predefined, stopping condition that has been automatically recognized as fulfilled. In other words, the method can be applied when the driver attempts to override the driver assistance function or its request or control signals by actuating the accelerator pedal, i.e., to override them and thereby set the motor vehicle in motion.A corresponding stopping condition can be met, for example, if there is an obstacle or, for example, another road user or the like in front of the motor vehicle in the set direction of travel, thus creating a risk of collision, or if a traffic light is red, or a pedestrian is approaching a pedestrian crossing located in front of the motor vehicle, or similar situations. In such situations, the invention can be particularly useful because it can alert the driver to a potential hazard, while at the same time allowing the driver to override the driver assistance function if, for example, the stopping condition was incorrectly detected as being met.If the invention is not applied in other situations, i.e. if the driver's desired torque is not reduced accordingly, a corresponding impairment of the driver can be avoided and the driver can thus be enabled to control the motor vehicle particularly quickly and directly and to offer a particularly high level of operating comfort.

[0021] In a possible further development of the present invention, the assistance system is configured to apply the method according to the invention only if the stopping condition is still met when the accelerator pedal is initially actuated. In other words, even when the motor vehicle is stationary, it is possible to continuously check whether the stopping condition is still met or fulfilled. As soon as this is no longer the case and the driver then actuates the accelerator pedal, the full driver command torque can be determined or used as the total target torque, for example. The further development of the present invention proposed here enables the assistance system or the motor vehicle to react flexibly and appropriately to different situations. This allows a high level of operating comfort to be achieved overall.

[0022] In a further possible embodiment of the present invention, the assistance system is designed to increase the assistance target torque to such an extent, i.e. to make it more negative or more decelerating, when the motor vehicle reaches or falls below a predetermined minimum distance from a location corresponding to the stopping condition, as a result of the actuation of the accelerator pedal. This means that the overall target torque becomes negative or decelerating. A location corresponding to the stopping condition can, for example, be the location or position of the respectively detected obstacle or a stop line at a traffic light or a marking on a pedestrian crossing or the like. According to the embodiment of the present invention proposed here, the driver can therefore, for example, be able to manually move the motor vehicle closer to or closer to a corresponding obstacle ora corresponding location can be enabled as long as the distance between the motor vehicle and the vehicle is greater than the specified minimum distance. However, this can be prevented if or as soon as the distance is or becomes smaller than the specified minimum distance. This can give the driver a certain degree of manual flexibility or control over the vehicle or its behavior, which can increase operating convenience and increase the acceptance of automated vehicle guidance functions. At the same time, a particularly high level of safety can be achieved.

[0023] In a further possible embodiment of the present invention, the assistance system is configured to preferably control only the electric drive motor to set the total target torque. In other words, the assistance system is configured to set the total target torque exclusively by means of the drive motor, as far as possible. To this end, the assistance system can, for example, communicate with a corresponding engine control unit of the drive motor and / or comprise a module for dividing or allocating the total target torque to various actuators. The embodiment of the present invention proposed here can enable particularly fast-responding control, i.e., a correspondingly fast and precise adaptation, i.e., changing the applied total torque, and thus create particularly high driving comfort.In addition, this can enable or support particularly efficient and environmentally friendly operation of the vehicle.

[0024] In a further possible embodiment of the present invention, the assistance system is configured to additionally control a braking system of the motor vehicle, which includes a friction brake, to provide a remaining portion of the total target torque only when the total target torque is negative, i.e., decelerating, and cannot be fully provided by the electric drive motor. The braking system can, in particular, be part of the drive system of the motor vehicle. The embodiment of the present invention proposed here ensures flexible and precise control even of relatively large decelerating torques with minimal use of the braking system, i.e., the friction brake.By initially utilizing the capacity of the electric drive motor to generate a decelerating torque and only generating a remaining portion or remainder of the total target torque by means of the braking system, wear on the friction brake and the generation of brake dust can be minimized. In particular, the assistance system can be configured to initially reduce or dissipate the decelerating torque generated by the braking system as the total target torque becomes more positive, i.e., changes toward a weaker deceleration, and only implement a further change in the total target torque by appropriately controlling the electric drive motor after the friction brake has been completely released.

[0025] In a further possible embodiment of the present invention, the assistance system is configured to use or determine the driver balance torque or total driver torque as the total target torque when the assistance target torque has a weaker deceleration effect than a driver balance torque or total driver torque, which is composed of the balance or sum of the driver's desired torque determined by the accelerator pedal position or the accelerator pedal torque and the offset torque, and the brake pedal torque. In other words, the driver is then solely responsible for controlling or determining the torque. The brake pedal torque depends on the current actuation of the brake pedal by the driver of the motor vehicle, i.e., a corresponding actuation position of the brake pedal.The brake pedal torque can be analogous to the accelerator pedal torque, for example linearly or according to a predetermined characteristic curve with the actuating position of the brake pedal, i.e. as a function of the actuating position or by means of a predetermined factor from the actuating position or a corresponding brake pedal angle. The embodiment of the present invention proposed here can achieve a high level of safety and enable the driver to precisely control or monitor the vehicle's behavior in potentially critical situations in which they desire, request, or set a correspondingly strong deceleration. This is based on the recognition that driver assistance functions available today, at least, cannot always operate absolutely reliably and error-free and that deceleration orStopping is safer or can lead to a safe vehicle condition more quickly or reliably than, for example, less severe deceleration or maintaining speed or even acceleration. The present invention also relates to a motor vehicle which is equipped with a driver assistance function or the driver assistance function mentioned elsewhere for at least assisted or at least partially automated longitudinal guidance of the motor vehicle. The motor vehicle according to the invention also has a drive system with an electric drive motor and the assistance system according to the invention. The motor vehicle according to the invention is therefore also designed to carry out the method according to the invention, in particular automatically. The motor vehicle according to the invention can in particular be the motor vehicle mentioned in connection with the method according to the invention and / or in connection with the assistance system according to the invention or correspond thereto.Accordingly, the motor vehicle according to the invention may have some or all of the properties and / or features mentioned in these contexts.

[0026] Further features of the invention may emerge 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 alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0027] The drawing shows:

[0028] Fig. 1 is a schematic representation of a motor vehicle that can be controlled manually and by means of a driver assistance system and is configured for comfortable, corresponding cooperative control; and

[0029] Fig. 2 shows an exemplary schematic diagram with temporal courses of various variables to illustrate the cooperative control.

[0030] Fig. 1 shows a schematic representation of a motor vehicle 1 with a drive system 2. This drive system 2 comprises an electric machine 3. The drive system 2 can also comprise, for example, an engine control unit (not shown in detail here) and / or electrical or electronic devices and / or the like. The motor vehicle 1 also has a traction battery 4 for supplying the electric machine 3 and a braking system or braking system 5, which can also be part of the drive system 2 or coupled thereto. The motor vehicle 1 can be manually controlled by a driver 6. To do so, the driver 6 can, for example, actuate an accelerator pedal 7 and / or a brake pedal 8 of the motor vehicle 1. Likewise, the motor vehicle 1 can be controlled or guided by a driver assistance system 9 in an assisted or at least partially automated operating mode.This driver assistance system 9 can therefore implement a corresponding driver assistance function which can, for example, request accelerating or decelerating drive or braking torques which can be provided, i.e. generated, by means of the drive system 2 if necessary.

[0031] It can then happen that the driver assistance system 9 and the driver 6 carry out different control interventions at the same time, i.e. request different torques. In order to handle such situations, the motor vehicle 1 here also has an assistance system 10. This can be coupled, for example, directly or indirectly, to the drive system 2 and the driver assistance system 9 via an interface 11. Via the interface 11, the assistance system 10 can, for example, record or monitor an operating position of the accelerator pedal 7 and the brake pedal 8 as well as a torque requested by the driver assistance system 9. To process corresponding data, the assistance system 10 has a processor 12 (shown schematically here) and a computer-readable data memory 13 coupled to it. The assistance system 10 can therefore generate corresponding control signals, which it can then transmit, for example, to the drive system 2 or the driver 6 via the interface 11.to the electric machine 3 or the braking system 5.

[0032] To illustrate the working or functional principle of the assistance system 10, Fig. 2 shows an exemplary diagram in which the curves of various variables or parameters are plotted over time t. A torque—that is, depending on the sign, positive drive torques or negative braking torques or deceleration torques—is plotted on one ordinate, and an accelerator pedal angle 0 is plotted on a second ordinate.

[0033] As an example for a specific driving situation, a curve of a total target torque 14 to be set is plotted here. Also shown are corresponding curves of an assistance target torque 15 requested by the driver assistance system 9, a predetermined constant negative, i.e., decelerating, offset torque 16, and a driver command torque 17. The driver command torque 17 results from the sum of the offset torque 16 and an accelerator pedal torque (not shown separately here for the sake of clarity), which results independently of the offset torque 16 solely from the current actuation or operating position of the accelerator pedal 7. In addition, an accelerator pedal angle curve 18 is also shown, which represents the operating position of the accelerator pedal 7, i.e., a corresponding actuation or accelerator pedal angle 0. The curves shown are indicated schematically and in a simplified manner.In a real implementation, for example, at least the torque-related curves not directly caused by the driver 6 can be smooth or differentiable curves or predefined characteristic curves.

[0034] In the driving situation depicted here, the motor vehicle 1 can initially, i.e. up to a first time t1, be or have been brought to a standstill by means of the driver assistance system 9 without manual intervention by the driver 6, i.e. in particular without manual actuation of the accelerator pedal 7 and the brake pedal 8. For this purpose, the assistance target torque 15 is correspondingly negative, here for example -100 Nm, and corresponds to the total target torque 14. At the same time, the accelerator pedal angle curve 18 is zero, or the accelerator pedal angle 0 is 0°. The offset torque 16, which is present even without actuation of the accelerator pedal 7, is constant at, for example, -500 Nm. Since the driver 6 neither actuates the accelerator pedal 7 nor the brake pedal 8, the corresponding accelerator pedal and brake pedal torques (not shown separately here for the sake of clarity) are zero, so that the driver's desired torque 17 corresponds to the offset torque 16.

[0035] The total torque 14 is therefore smaller than the driver's desired torque 17 by the difference between the assistance target torque 15 and the offset torque 16.

[0036] Before time t1, the total torque resulting from the accelerator pedal 7, i.e. the driver desired torque 17, is at the negative offset torque 16, while the driver assistance system 9 requests a negative acceleration, which on the level or in combination with a possible gradient compensation results in the negative assistance desired torque 15, which is more negative, i.e. more decelerating, than the offset torque 16 or the driver desired torque 17. The motor vehicle 1 can be braked to a standstill by the correspondingly negative total desired torque 14.

[0037] However, the driver 6 should now be able to move forward by manually actuating the accelerator pedal 7, for example to get closer to an obstacle ahead. To do this, the driver 6 actuates the brake pedal 8 at time t1 in the present case. The accelerator pedal angle curve 18 then increases from 0 = 0° via a first accelerator pedal angle θ1, which is reached at a later time t2, and a second accelerator pedal angle θ2, which is reached at an even later time t3, up to a maximum. Since the assistance target torque 15 is still more negative than the offset torque 16, the driver command torque 17 is reduced by the difference between the assistance target torque 15 and the offset torque 16 in order to determine the total target torque 14 to be set. In the present case, the driver command torque 17 already reaches a value of zero at time t2, so that without the assistance target torque 15 the motor vehicle 1 would start moving from this point in time.In this case, however, the total target torque 14 is still negative at time t2. Only with further actuation of the accelerator pedal 7 up to the second accelerator pedal angle 02 does the total target torque 14 also reach a value of zero at the later time t3, so that the motor vehicle 1 only begins to move at this later time t3 or with a correspondingly stronger actuation of the accelerator pedal 7.

[0038] In the exemplary progression shown here, the driver 6 holds the accelerator pedal 7 in the same operating position for a certain period of time and releases it again at a time t4. Accordingly, the driver's desired torque 17 also follows a similar progression and, after a plateau and a subsequent drop, reaches a value of zero at a later time t5. It then continues to fall to the offset torque 16 until a yet later time t6, so that the accelerator pedal torque is zero. At this time t6, the accelerator pedal 7 is completely released, i.e., it is in its zero or neutral position without any actuation by the driver 6.

[0039] For example, driver assistance system 9 has meanwhile increased the assistance target torque 15, thus requesting greater deceleration. Since the driver's desired torque 17 continues to be reduced by the difference between the current value of the assistance target torque 15 and the offset torque 16, the total target torque 14 drops despite the driver's desired torque 17 remaining constant during the plateau. From time t6, at which the accelerator pedal torque is zero, the total target torque 14 then again corresponds to the assistance target torque 15. Since this remains negative, motor vehicle 1 can then come to a standstill again.

[0040] Overall, the examples described show how balancing cooperativity between automated and manual driving can be realized and applied.

[0041] List of reference symbols

[0042] 1 Motor vehicle 2 Drive system

[0043] 3 electric machine

[0044] 4 Battery 5 Brake system

[0045] 6 Driver 7 Accelerator pedal

[0046] 8 Brake pedal 9 Driver assistance system 10 Assistance system 11 Interface 12 Processor 13 Data memory

[0047] 14 Total target torque 15 Assistance target torque 16 Offset torque 17 Driver request torque

[0048] 18 Accelerator pedal angle curve 0 Accelerator pedal angle 01 first accelerator pedal angle 02 second accelerator pedal angle t Time t1 - t6 Time points

Claims

Patent claims 1. Method for controlling a drive system (2) of a motor vehicle (1) comprising an electric drive machine (3), wherein automatically - an actuation position of an accelerator pedal (7) of the motor vehicle (1) is monitored and a corresponding driver request torque (17) is determined, which is composed of a predetermined decelerating offset torque (16) which is active even without actuation of the accelerator pedal (7) and an accelerator pedal torque which is dependent on the actuation position of the accelerator pedal (7), - monitoring is carried out for a decelerating assistance target torque (15) requested by a driver assistance function (9) for at least assisted longitudinal guidance of the motor vehicle (1), - if the assistance target torque (15) is more decelerating than the offset torque (16), at least when the accelerator pedal (7) is actuated, the corresponding driver request torque (17) is reduced by the difference between the assistance target torque (15) and the offset torque (16) in order to determine a total target torque (14), and - the drive system (2) is controlled to set the total target torque (14).

2. Assistance system (10) for a motor vehicle (1), comprising an input interface (11) for detecting pedal data corresponding to an operating position of an accelerator pedal (7) of the motor vehicle (1) and driver assistance function data which indicate an assistance target torque (15) requested by a driver assistance function (9) for at least assisted longitudinal guidance of the motor vehicle (1), a data processing device (12, 13) for processing the detected data and for determining a corresponding total target torque (14) and for generating a corresponding control signal, and an output interface (11) for outputting the respective control signal, wherein the assistance system (10) is set up to carry out the method according to claim 1.

3. Assistance system (10) according to claim 2, characterized in that the assistance system (10) is designed to apply the method, in particular only when the initial actuation of the accelerator pedal (7) occurs when the motor vehicle (1) is at a standstill, after the driver assistance function (9) has automatically brought the motor vehicle (1) to a standstill on the basis of a predetermined stopping condition that is automatically recognized as being fulfilled.

4. Assistance system (10) according to claim 3, characterized in that the assistance system (10) is designed to apply the method only if the stopping condition is still met upon initial actuation of the accelerator pedal (7).

5. Assistance system (10) according to claim 3 or 4, characterized in that the assistance system (10) is designed to increase the assistance setpoint torque (15) to such an extent that the total setpoint torque (14) becomes decelerating when the motor vehicle (1) reaches or falls below a predetermined minimum distance from a location corresponding to the stopping condition due to the actuation of the accelerator pedal (7).

6. Assistance system (10) according to one of claims 2 to 5, characterized in that the assistance system (10) is designed to preferably control only the electric drive machine (3) to set the total target torque (14).

7. Assistance system (10) according to one of claims 2 to 6, characterized in that the assistance system (10) is set up to additionally control a braking system (5) of the motor vehicle (1), which comprises a friction brake, to set a remaining portion of the total target torque (14) only when the total target torque (14) is retarding and cannot be completely set by means of the electric drive machine (3).

8. Assistance system (10) according to one of claims 2 to 7, characterized in that the assistance system (10) is designed to, when the Assistance target torque (15) is less decelerating than a driver balance torque, which is composed of the driver desired torque (17) and a Brake pedal torque, which is dependent on a current actuation position of a brake pedal (8) of the motor vehicle (1), to determine the driver balance torque as the total target torque (14).

9. Motor vehicle (1) equipped with a driver assistance function (9) for at least assisted longitudinal guidance of the motor vehicle (1), and having a drive system (2) with an electric drive motor (3) and the assistance system (10) according to one of claims 2 to 8.

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