Procedures for operating a motor vehicle

Abstract

The invention relates to a method for operating a motor vehicle (2) that has an electric steering system (4) for automatic steering and a driver assistance system (10) for a hands-off driver assistance function. The motor vehicle (2) is steered automatically by means of the driver assistance system (10). During automatic steering, the steering process of the motor vehicle (2) is monitored by the driver assistance system (10), and if an incorrect steering process is detected as a result of the monitoring, a signal (S) is generated. D ) to deactivate the automatic steering from the driver assistance system (10) to the steering system (4), so that the automatic steering is deactivated.

Description

[0001] The invention relates to a method for operating a motor vehicle having an electric steering system and a driver assistance system for a hands-off driver assistance function. Furthermore, the invention relates to such a motor vehicle.

[0002] Motor vehicles can be equipped with advanced driver assistance systems (ADAS) to support the driver in certain driving tasks. For example, such a driver assistance system provides adaptive cruise control (ACC), emergency braking assistance, or lane centering as assistance functions.

[0003] According to the SAE J3016 standard, automated driving is divided into six levels. At Level 2, the class for partially automated driving, the steering and / or acceleration of the vehicle is taken over by one or more such driver assistance systems, depending on the driving mode. The driver is expected to assume all other driving tasks and be able to take over control of the vehicle at any time, for example, to intervene correctively.

[0004] Hands-off driver assistance systems (hands-free driver assistance systems) are also known for a hands-off driver assistance function, in which the vehicle is automatically controlled by the driver assistance system without the driver having to steer the vehicle, i.e., without the driver operating the steering wheel. In this case, the steering and, for example, the longitudinal acceleration of the vehicle are performed automatically.

[0005] For example, a steering system rated as ASIL QM according to ASIL ("Automotive Safety Integrity Level," see ISO 26262) and configured for automatic lateral guidance is typically sufficient for driver assistance systems where the driver always takes over the steering. However, in a hands-off driver assistance system where the driver is not currently operating the steering wheel, a steering error, such as a failure of the automatic steering function or over- or under-steering, would result in an increased risk of an accident.

[0006] US Pat. No. 11,169,520 B2 discloses a system for a vehicle comprising a first and a second control unit. The first and second control units are programmed to monitor a first operating condition and a second operating condition, respectively. For example, the operating condition is a path deviation, a lane width, a user perception, or a steering torque. The first or second control unit is programmed to control vehicle operation based on the first or second operating condition.

[0007] WO 2023 / 030 722 A1 describes a device for a vehicle. When a hands-free assistance function is activated and a braking system fault is detected, a braking jolt is generated by the braking system. This alerts the driver to the current situation.

[0008] Furthermore, it is known, for example, also from WO 2023 / 030 722 A1, that a redundant steering system is used in motor vehicles to ensure sufficient safety in hands-off driver assistance systems. This is used for automatic steering if a fault occurs in the primary steering system during an active hands-off driver assistance function. The disadvantage of such a redundant steering system is that it increases the cost of the motor vehicle.

[0009] The invention is based on the objective of enabling the safest possible journey with an activated hands-off driver assistance function. In particular, the structural, i.e., hardware, complexity should be kept to a minimum.

[0010] With regard to the method, the object is achieved according to the invention by a method for operating a motor vehicle having the features of claim 1. Furthermore, this object is achieved according to the invention by a motor vehicle having the features of claim 8, by a computer program product having the features of claim 9, and by a computer-readable medium having the features of claim 10. Advantageous embodiments and further developments are the subject of the subclaims. The statements in connection with the method also apply mutatis mutandis to the motor vehicle, the computer program product, and the computer-readable medium, and vice versa.

[0011] The method serves to operate a motor vehicle, hereinafter also referred to as a vehicle. This comprises an electric steering system, preferably a 4-wheel steering system (electric power steering system) with a mechanical connection between its steering column and its rack. The steering system is configured for automatic steering, i.e., for automatic lateral guidance of the motor vehicle, and expediently also for manual steering. A 4-wheel steering system comprises an electric motor that provides torque, for example, to the rack, a steering gear pinion, or the steering line of the steering system, in order to assist manual steering by the driver and / or to steer the motor vehicle automatically.In other words, the steering system is designed so that steering can be carried out manually, i.e. mechanically by a driver using a steering wheel, and / or automatically, in particular according to a predetermined steering torque and / or steering angle.

[0012] The motor vehicle further comprises a driver assistance system for a hands-off driver assistance function. The driver assistance system is therefore intended and configured to perform the hands-off driver assistance function, i.e., to support the driver accordingly. The hands-off driver assistance function is suitably a driver assistance function for driving on a road along a lane, with automatic lateral guidance and preferably also with automatic longitudinal guidance, i.e., braking or accelerating the (motor) vehicle without the driver operating the steering wheel. For example, the hands-off driver assistance function is intended for driving on a motorway or a country road.

[0013] The driver assistance function is activated automatically, for example, when the driver takes their hand off the steering wheel. Preferably, however, the driver assistance function is only activated when the driver activates the driver assistance function, for example using a control element or voice input. The driver assistance function is deactivated, for example, if a lane is not detected with sufficient reliability - for example, due to a failure or error of a camera system - and / or if the driver applies the brakes, in this case particularly if a predefined braking torque is exceeded. Furthermore, for example, the driver assistance function is deactivated if the driver operates the steering wheel and exerts a torque on the steering wheel, i.e. a so-called manual torque, that exceeds a predefined threshold value, such as 3 Nm.In other words, the driver assistance function is terminated if the driver overrides the automatic steering and the manual torque exceeds the threshold.

[0014] For practical purposes, the driver can operate the steering wheel and thus intervene in the steering even when the driver assistance function is activated. The driver assistance function is terminated if the manual torque exceeds the threshold. The driver assistance function therefore remains active as long as the threshold is not exceeded (or unless another reason for deactivation applies).

[0015] Preferably, the driver assistance function is not deactivated as soon as the driver has one hand on the steering wheel.

[0016] The driver assistance system or the hands-off driver assistance function performed by it is assigned to Level 2 for partially automated driving according to the “SAE J3016” standard.

[0017] In the method, the motor vehicle is first steered automatically by the driver assistance system, in particular by means of its hands-off driver assistance function, i.e. without the driver steering using the steering wheel, in other words automatically guided laterally. For this purpose, steering signals and / or steering data are expediently provided by the driver assistance system in order to guide the motor vehicle along a target trajectory determined by the driver assistance system. The target trajectory is suitably selected such that the motor vehicle is guided, preferably entirely, in the current lane. The lane center line of a lane on the road, in particular the lane on the road currently being used by the motor vehicle, is used as the target trajectory. Furthermore, for example, the target trajectory is at a distance from the lane center line. The corresponding distance is expediently determined as a function of the current driving situation.For example, the vehicle is guided to the left of the lane center line in terms of direction of travel if a truck is driving in the adjacent right lane or an obstacle is narrowing this adjacent lane. The steering signals and / or steering data are transmitted to the steering system, so that the vehicle is steered according to these steering signals and / or steering data.

[0018] During automatic steering of the motor vehicle, i.e., when the vehicle is automatically guided laterally by the steering system, the vehicle's steering action is monitored by the driver assistance system. The driver assistance system monitors the result of the steering performed by the steering system. In other words, the driver assistance system monitors the automatic steering for any incorrect behavior.

[0019] According to the procedure, if an incorrect steering operation is detected as a result of the steering process monitoring, the driver assistance system issues a (deactivation) signal to the steering system to deactivate the automatic steering. Specifically, this signal is issued as soon as the steering operation is identified as incorrect; in other words, the signal is issued immediately after the error is detected.

[0020] A steering error occurs particularly when understeering or oversteering occurs, i.e., when the steering angle is set too small or too large to follow a curve. Alternatively or additionally, a steering error occurs particularly when the automatic steering system fails. In these cases, the vehicle deviates from the target trajectory.

[0021] The signal is transmitted, for example, directly to the steering system or via a CAN bus of the vehicle to the steering system.

[0022] In summary, the signal for deactivating the automatic steering is intended to deactivate the automatic steering, i.e. to ensure that the motor vehicle is no longer guided automatically, in particular not according to the target trajectory.

[0023] In summary, the driver assistance system monitors the steering system indirectly by monitoring the steering process, and automatically deactivates the steering by outputting a deactivation signal to the steering system. In addition to supporting the driver, the driver assistance system also performs the functions of monitoring the steering process and, if necessary, deactivating the steering system. This ensures comparatively safe and reliable operation of the motor vehicle within the scope of the hands-off driver assistance function. A second steering system in addition to the (first) steering system as a fallback in the event of a fault in the first steering system is not necessary and is not used for practical purposes.

[0024] The steering system also conveniently includes a monitoring function to ensure the functionality of its components. For example, the automatic steering function is deactivated if the electric motor issues an error signal, if a steering system sensor fails, and / or if automatic steering cannot be performed.

[0025] According to a suitable embodiment, when the steering is deactivated, preferably until the driver takes over the steering or for a predefined period of time, no torque for the automatic steering is provided by the electric motor of the steering system.

[0026] Therefore, the steering angle of the vehicle is no longer adjusted by the automatic steering system.

[0027] Additionally or alternatively, when the steering is deactivated, preferably until the driver takes over steering or for a predefined period of time, the last set, i.e., current, steering angle is retained, i.e., "frozen." In this case, the steering angle remains constant over time. Thus, the angle last set during automatic steering between the wheel axle and a vehicle axis, for example, the vehicle's longitudinal axis, is maintained constant. In this way, an undefined change in the direction of travel is avoided, particularly in the event of a failure of the automatic steering, and the vehicle moves at least approximately according to the specified target trajectory.

[0028] For example, a device external to the steering system is used to monitor the steering process.

[0029] According to a suitable embodiment, a deviation of the motor vehicle from the predetermined target trajectory for the automatic steering is determined to monitor the steering process. For example, a distance of a center line of the motor vehicle or its center point from the target trajectory is determined for this purpose. If this distance is greater than a predetermined first threshold value and / or if this distance is exceeded for a period of time greater than a predetermined second threshold value, an incorrect steering process is deemed to have been detected. Additionally or alternatively, a deviation of the current course angle of the motor vehicle from a (pre-calculated) course angle for driving along the target trajectory is determined. If this deviation is greater than a predetermined third threshold value and / or if this deviation is exceeded for a period of time greater than a predetermined fourth threshold value, an incorrect steering process is deemed to have been detected.Additionally or alternatively, a deviation of the current steering angle from a (pre-calculated) steering angle for driving along the target trajectory is determined. If this deviation is greater than a predefined fifth threshold and / or is exceeded for a period of time greater than a predefined sixth threshold, an incorrect steering maneuver is considered detected.

[0030] Advantageously, over-steering or under-steering can and / or will be determined based on these comparisons.

[0031] To determine the desired trajectory, to determine the deviation of the motor vehicle from the desired trajectory, to determine the deviation of the current heading angle and / or the deviation of the current steering angle, image and / or video data are suitably transmitted from a camera system of the motor vehicle to the driver assistance system, and these are then evaluated accordingly by the driver assistance system. For a comparatively reliable determination of the desired trajectory, for example based on a recognized lane, the camera system preferably comprises a stereo camera and, for example, additionally uses a multifunction camera. The camera system in particular forms the steering system-external device for monitoring the steering process or is a part thereof. Alternatively or additionally, a high-resolution (HD) map of the road can be used, which is made available to the driver assistance system.

[0032] According to a suitable embodiment, a lateral jerk is detected to monitor the steering process. For this purpose, an inertial sensor is used in particular, which is connected to the driver assistance system via signal and / or data transmission. Using the inertial sensor, the lateral jerk can be detected as an acceleration or force in the transverse direction of the vehicle. Such a lateral jerk occurs in particular in the event of a failure of the automatic steering, in particular in the event of an abrupt failure, i.e. when the electric motor of the steering system no longer provides torque for the automatic steering, in particular suddenly. Such a malfunction occurs, for example, when the steering system, in particular a control device thereof, does not output a signal or outputs an incorrect control signal to the electric motor and / or when the control device is no longer provided with steering signals and / or steering data.If the detected lateral jerk is greater than a predefined seventh threshold, a steering error is considered to have been detected. The seventh threshold is appropriately determined depending on the current vehicle speed, the current curve radius, and / or the condition of the vehicle, in particular its dampers and / or suspension.

[0033] In a preferred embodiment, the torque provided by the electric motor of the steering system for the automatic steering of the motor vehicle and / or a temporal change in this torque during automatic steering is limited. In particular, this is limited such that a rack force resulting from the provided torque is less than, for example, 300 N or less than 3000 N, and / or that a temporal change in the rack force is less than or equal to 15000 N / s. In summary, the rack force provided for the automatic steering and / or its temporal force is limited.

[0034] Additionally or alternatively, in an advantageous embodiment, the torque provided by the electric motor of the steering system for the automatic steering of the motor vehicle is limited during automatic steering such that the automatic steering can be overridden based on the manual torque applied by the driver, with this override occurring, for example, from 3 Nm of manual torque. In summary, the automatic steering can be overridden from a predetermined value for the manual torque, for example, 3 Nm. In other words, the driver can fully assume the steering task from a manual torque of 3 Nm, in particular, even adjust the steering angle counter to the torque applied by the electric motor.

[0035] In this way, it is not difficult for the driver to take over the steering task and / or injury to the driver due to excessive steering torque is avoided.

[0036] According to a practical embodiment, the vehicle is decelerated, preferably automatically, when a steering error is detected. Thus, in response to the detection of a steering error, a brake of the motor vehicle is activated, causing the motor vehicle to decelerate. Due to such a deceleration of the vehicle—with automatic steering deactivated (and in particular, if the driver has not yet taken over steering control)—the time until the currently used lane is left is increased. This advantageously increases the time for the driver to take over steering control, and / or reduces the risk of an accident.

[0037] According to an expedient development, alternatively or additionally, a warning and / or a takeover request is issued to the driver. For this purpose, the driver assistance system controls an output device accordingly. For example, the driver assistance system controls a display and / or a loudspeaker in such a way that a visual or acoustic signal is issued to the driver as a warning and / or a takeover request.

[0038] A further aspect of the invention relates to a motor vehicle which is and / or can be operated according to the method in one of the variants described above.

[0039] For this purpose, the motor vehicle comprises an electric steering system, preferably a four-wheel steering system. This in turn comprises a first control device (steering control device, first control unit) and an electric motor for providing torque to assist manual steering by the driver and / or for automatic steering of the motor vehicle, i.e., for automatic lateral guidance of the motor vehicle. The electric motor is controlled by the first control device.

[0040] The motor vehicle further comprises a driver assistance system for a hands-off driver assistance function. The driver assistance system comprises a control device, which is referred to here and below as a second control device or second control unit for the purpose of better distinguishing it from the control device of the steering system. This control device is connected to the first control device of the steering system via signal and / or data transmission technology. The first and second control devices are preferably structurally separate from one another. In summary, the steering system has one control device, referred to as the "first control device," and the driver assistance system has another control device, referred to as the "second control device."

[0041] The first and second control devices are provided and configured to carry out the method in one of the variants described above.

[0042] In particular, the second control device is provided and configured to evaluate image and / or video data from a camera system and to use this data to determine a desired trajectory for the motor vehicle. The second control device is expediently further configured to generate steering signals and / or steering data and output them to the steering system, wherein the steering signals and / or steering data are configured such that the motor vehicle is automatically steered by the steering system in accordance with the desired trajectory. Furthermore, the second control device is provided and configured to check the steering process for faulty steering. For this purpose, the second control device is provided and configured to evaluate the image and / or video data and / or data provided by an inertial sensor with regard to a deviation of the motor vehicle from the desired trajectory or with regard to a lateral jerk.Preferably, the second control device is provided and configured to control an output device such as a display or a loudspeaker in such a way that it outputs a warning and / or a takeover request to the driver when an incorrect steering operation is detected.

[0043] In particular, the first control device is provided and configured to receive steering signals and / or steering data provided by the second control device and to control the electric motor of the steering system for automatic lateral guidance of the motor vehicle in accordance with these steering signals and / or steering data. Additionally or alternatively, the first control device is provided and configured to deactivate the automatic lateral guidance of the motor vehicle upon receipt of a signal provided by the second control device for deactivating the automatic steering. For example, the electric motor is controlled for this purpose in such a way that it no longer provides any torque for automatic steering, or that the last set steering angle is kept constant.

[0044] A further aspect of the invention relates to a computer program product. This comprises instructions that cause the motor vehicle, in one of the variants described above, to perform the steps of the method in one of the variant methods described above.

[0045] The computer program product expediently comprises (first) program code with instructions for the first control device, i.e. for the control device of the steering system, and (second) program code with instructions for the second control device.

[0046] In particular, the first program code, when executed by the first control device, causes the electric motor of the steering system to be controlled for automatic lateral guidance of the motor vehicle in accordance with steering signals and / or steering data provided by the second control device. Additionally or alternatively, the first program code causes the automatic lateral guidance of the motor vehicle to be deactivated upon receipt of a signal provided by the second control device for deactivating the automatic steering. For example, the first program code causes the electric motor to be controlled in such a way that it no longer provides torque for automatic steering, or that the last set steering angle is kept constant.

[0047] For example, when executed by the second control device, the second program code causes image and / or video data from a camera system to be evaluated, and on the basis of this, a desired trajectory for the motor vehicle is determined. When executed by the second control device, the second program code expediently also causes steering signals and / or steering data to be generated and output to the steering system, wherein the steering signals and / or steering data are designed such that the motor vehicle is automatically steered by the steering system in accordance with the desired trajectory. Furthermore, when executed by the second control device, the second program code preferably causes a steering process of the motor vehicle to be checked for faulty steering.For this purpose, the image and / or video data and / or data provided by an inertial sensor are evaluated with regard to a deviation of the motor vehicle from the target trajectory or with regard to a lateral jerk. Preferably, the second program code, when executed by the second control device, additionally or alternatively causes an output device, such as a display or a loudspeaker, to be controlled in such a way that it issues a warning and / or a takeover request to the driver if an incorrect steering maneuver is detected.

[0048] A further aspect of the invention relates to a computer-readable medium on which the above-described computer program product, in particular the first program code and / or the second program code, is stored. Alternatively, a first computer-readable medium with the first program code and a second computer-readable medium with the second program code are provided. The or each computer-readable medium is expediently a hard disk or a memory installed in the vehicle; alternatively, the computer-readable medium is a portable storage medium, such as a flash memory, a CD, or a DVD.

[0049] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In the drawings: Fig. 1 schematically shows a motor vehicle having an electric steering system and a driver assistance system for a hands-off driver assistance function, and Fig. 2 shows a flow chart showing a procedure for operating the motor vehicle.

[0050] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0051] In the Fig. 1 schematically shows a motor vehicle 2. This comprises an electric steering system 4 with a first control device 6 and an electric motor 8 for providing a torque to assist manual steering by the driver and / or for purely automatic steering, i.e., for automatic lateral guidance. The electric motor 8 is connected to the first control device 6 via signal and / or data transmission, so that the electric motor 8 can be controlled by the first control device 6. For this purpose, the first control device 6 outputs a corresponding motor control signal S EM to the motor. Optionally, the electric motor 8 can send a signal S Zabout the state of the electric motor, for example comprising information about the speed, a rotor position, or about a defect or faulty operation of the electric motor 8, to the first control device 6.

[0052] Furthermore, the motor vehicle 2 comprises a driver assistance system 10 that provides a hands-off driver assistance function 12a. When the hands-off driver assistance function 12a is activated, the motor vehicle 2 is guided laterally by means of the driver assistance function 12a. In other words, the driver does not steer, but rather the motor vehicle 2 is steered automatically when the hands-off driver assistance function 12a is activated.

[0053] The driver assistance system 10 comprises a second control device 12, which is structurally separate from the first control device 6. The first and second control devices 6, 12 are connected to one another via signal and / or data transmission.

[0054] The driver assistance system 10 is connected by signal and / or data transmission to a camera system 14, which according to the embodiment shown here comprises a stereo camera 16 and a multifunctional camera 18. In this way, image and / or video data D B , which are provided by the camera system 14, can be transmitted to the driver assistance system 10, in particular to its second control device 12.

[0055] Furthermore, the driver assistance system 10, in particular its second control device 12, is connected to an inertial sensor 20 in terms of signal and / or data transmission technology, so that measurement data provided by the inertial sensor 20 can be supplied to the driver assistance system 10.

[0056] The driver assistance system 10 is preferably further configured to control an output device 22, which is embodied here, for example, as a loudspeaker, and / or a brake BS. For this purpose, the second control device 12 is analogously connected to the output device 22 or to the brake 24 via signal and / or data transmission.

[0057] In the Fig. 2 is a flow chart illustrating a method for operating the device shown in Fig. 1. In particular, the first and second control devices 6, 12 are coupled to one another via signal and / or data transmission to carry out the method.

[0058] To carry out the method, the electric steering system 4 further comprises a first non-volatile memory 26 as a computer-readable medium, which is coupled to the first control device 6. Furthermore, the driver assistance system 10 comprises a second non-volatile memory 30 as a computer-readable medium, which is coupled to the second control device.

[0059] In a first step I (and during the second step II, see below) of the method, the motor vehicle 2 is steered automatically using the hands-off driver assistance function 12a, i.e., without the driver using the steering wheel. For this purpose, the driver assistance system uses the image and / or video data D provided by the camera system. B evaluated and a target trajectory is determined. Subsequently, steering signals S L(and / or steering data in a manner not shown in detail) for automatically guiding the motor vehicle along the desired trajectory and transmitting these to the steering system 4. The first control device 6 controls the electric motor 8 according to the steering signals S L so that the motor vehicle 2 travels along the target trajectory.

[0060] For this purpose, a second program code 32 is stored on the second memory 30, which includes commands which, when executed by the second control device 12, cause the image and / or video data D B evaluated, the target trajectory is determined, and the steering signals S L for the steering system 4.

[0061] For this purpose, a first program code 28 is stored on the first memory 26, which includes commands which, when executed by the first control device 6, cause the electric motor 8 to rotate in accordance with the steering signals S Lis controlled to automatically guide the motor vehicle 2 transversely and / or longitudinally.

[0062] Preferably, during the automatic steering in steps I and II, a torque provided by the electric motor 8 and / or a temporal change thereof is limited, so that the driver can take over steering easily and / or safely.

[0063] In a second step II, which is performed during automatic steering after step I, a steering maneuver of motor vehicle 2 is monitored using driver assistance system 10 for any malfunction, i.e., an incorrect steering maneuver. A steering maneuver error is understood to mean, in particular, understeering, oversteering, and / or a failure of the automatic steering system. In these cases, motor vehicle 2 deviates from the target trajectory.

[0064] To monitor the steering process, a deviation of motor vehicle 2 from the target trajectory is determined.

[0065] For example, a distance d A a center line of the vehicle or its center point to the target trajectory. In addition or alternatively, a deviation d K of the current heading angle (for example, relative to 0° north) of the motor vehicle 2 from a heading angle for driving along the target trajectory. In addition or alternatively, a deviation d L The current steering angle is determined from a (pre-calculated) steering angle for driving along the target trajectory. For this purpose, information about the current steering angle is conveniently transmitted from the steering system 4 to the driver assistance system 10.

[0066] If at least one of the deviations is A , d K , d Lgreater than a given threshold value, a faulty steering operation is deemed to have been detected.

[0067] Alternatively or additionally, a lateral jerk a is used to monitor the steering process. Q For this purpose, the data provided by the inertial sensor 20 are evaluated. Thus, an acceleration or force in the transverse direction of the motor vehicle 2 is determined. Since such a transverse jerk a Q In particular, if there is an abrupt failure of the automatic steering, such a failure and the associated faulty steering operation are deemed to be detected if a specified or specifiable threshold value for the lateral jerk a Q is exceeded.

[0068] The second program code 32 comprises corresponding commands which effect such monitoring of the steering process.

[0069] In step III, if a faulty steering operation has been detected as a result of the monitoring, the driver assistance system 10, in particular its second control device 12, sends a (deactivation) signal S D generated and output to the steering system 4, in particular to its first control device 6.

[0070] For this purpose, the second program code comprises 28 instructions that generate and transmit the deactivation signal S D to the steering system 4.

[0071] Upon receipt of the signal S D the automatic steering is deactivated. The signal S D In summary, it is designed to deactivate automatic steering. In other words, automatic steering is terminated.

[0072] When the automatic steering is deactivated, the electric motor 8 is controlled, for example, by the first control device 6 in such a way that the electric motor 8 does not provide any torque for the automatic steering, for example, by not energizing its coils. In particular, no torque is provided for a predetermined period of time, or until the driver has taken over steering and a corresponding signal has been output from the driver assistance system 10 to the steering system 4.

[0073] Alternatively, when the steering is deactivated, the steering angle last set during automatic steering is maintained constant. For example, the electric motor 8 is controlled in such a way that it compensates for a force acting on the wheels of the motor vehicle 2.

[0074] The first program code 28 includes commands that deactivate the automatic steering upon receipt of the signal S Dcause.

[0075] Furthermore, in step III, the motor vehicle 2 is braked if an incorrect steering maneuver has been detected. Thus, the brake 24 is controlled, for example, directly or alternatively by means of a higher-level control device (not shown) based on the second control device 12 in such a way that the motor vehicle 2 brakes automatically, i.e., its speed is reduced.

[0076] For this purpose, the second program code 2 comprises commands which cause a corresponding control signal to be output to the brake 24 when an incorrect steering operation has been detected.

[0077] Alternatively, or preferably additionally, in step III, a warning and / or a request to take over the steering task is issued to the driver if an incorrect steering operation has been detected. For this purpose, the output device 22 is controlled by the second control device 12 in such a way that the warning or the request to take over is issued. For example, a corresponding acoustic signal is issued via the loudspeaker.

[0078] For this purpose, the second program code 32 comprises instructions which cause a corresponding control signal to be output to the output device 22 when an incorrect steering operation has been detected.

[0079] The first program code 28 and / or the second program code 32 forms a computer program product 34.

[0080] Optionally, a status signal S Stransmitted from the first control device 6 to the second control device 12. This signal includes, for example, information about the state of the steering system, in particular whether automatic lateral guidance is being carried out, and / or information about an error in the steering system 4. If the status signal S S For example, if information is provided that the steering system 4 is faulty or not functioning and / or that automatic steering is not being carried out, the hands-off driver assistance function 12a is terminated and / or the driver is requested to take over the steering.

[0081] In summary, the driver assistance system 10 provides both a hands-off driver assistance function 12a, within the scope of which an automatic lateral guidance and preferably additionally automatic longitudinal guidance of the motor vehicle takes place, as well as a monitoring and / or deactivation function 12b, which monitors the steering process and, upon detection of faulty steering, outputs the deactivation signal S D causes.

[0082] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can be derived from them by those skilled in the art within the scope of the claims without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments and / or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention. List of reference symbols 2 motor vehicles 4 Steering system 6 first control device 8 Electric motor 10 Driver assistance system 12 second control device 12a Function for automatic lateral guidance 12b Monitoring and deactivation function 14 Camera system 16 stereo camera 18 multifunction camera 20 Inertial sensor 22 Output device 24 Brake 26 first storage 28 first program code 30 second storage 32 second program code 34 Computer program product a Q Lateral pressure D B Image and / or video data d A Distance d K Deviation of the course angle d L Deviation of the steering angle S D Deactivation signal S EM Control signal for the electric motor S L steering signal S S status signal S Z status signal I Automatic steering of the motor vehicle using the driver assistance system II Monitoring the steering process using the driver assistance system III Deactivating automatic steering QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 11,169,520 B2

[0006] WO 2023 / 030 722 A1 [0007, 0008] Cited non-patent literature

[0000] ISO 26262

[0005]

Claims

[1] Method for operating a motor vehicle (2) which has an electric steering system (4) for automatic steering and a driver assistance system (10) for a hands-off driver assistance function (12a), - wherein the motor vehicle (2) is automatically steered by means of the driver assistance system (10), - wherein during automatic steering, a steering operation of the motor vehicle is monitored by means of the driver assistance system (10), - wherein, if a faulty steering operation is detected as a result of the monitoring, the driver assistance system (10) sends a signal (S D ) to deactivate the automatic steering to the steering system (4) so that the automatic steering is deactivated. [2] Method according to claim 1, characterized by that when the steering is deactivated, no torque is provided for automatic steering and / or that when the steering is deactivated, the last set steering angle is maintained. [3] Method according to claim 1 or 2, characterized by that in order to monitor the steering process, a deviation (d A , d K , d L ) of the motor vehicle (2) is determined by a predetermined target trajectory for the automatic steering. [4] Method according to one of claims 1 to 3, characterized by that a lateral jerk (a Q ) is recorded. [5] Method according to one of claims 1 to 4, characterized by that a torque and / or a temporal change thereof is limited for automatic steering. [6] Method according to one of claims 1 to 5, characterized by that the motor vehicle (2) is braked if an incorrect steering operation is detected. [7] Method according to one of claims 1 to 6, characterized by that a warning and / or a request to take over the steering task is issued to the driver. [8] Motor vehicle (2), comprising an electric steering system (4) for automatic steering and a driver assistance system (10) for a hands-off driver assistance function (12a), wherein the steering system (4) comprises a first control device (6) and the driver assistance system comprises a second control device (12) for carrying out the method according to one of claims 1 to 7. [9] Computer program product (28, 32, 34) comprising instructions which cause the motor vehicle (2) according to claim 8 to carry out the steps of the method according to one of claims 1 to 7. [10] A computer-readable medium (26,30) on which the computer program product (34) according to claim 9 is stored.

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