Method for operating a motor vehicle in which two driver assistance systems are activated

Abstract

Method for operating a motor vehicle (1) in which two driver assistance systems (8, 9) are activated, the method comprising the following steps: - Providing (S1) in the motor vehicle (1) environmental data (13) describing an environment of the motor vehicle (1) and driver state data (14) describing a state of a driver of the motor vehicle (1); - checking (S2) by means of a first driver assistance system (8) of the two driver assistance systems (8, 9) activated in the motor vehicle (1) whether the driver of the motor vehicle (1) is fit to drive or unfit to drive by evaluating the driver status data (14), wherein the first driver assistance system (8) is at least designed to partially or completely assume longitudinal guidance of the motor vehicle (1); - if it is determined that the driver is unfit to drive; transmitting (S3) an item of unfitness to drive information (16) describing the driver's unfitness to drive from the first driver assistance system (8) to a second driver assistance system (9) of the two driver assistance systems (8, 9) activated in the motor vehicle (1), wherein the second driver assistance system is designed to at least counteract a collision of the motor vehicle (1) with an object (2) arranged in front of the motor vehicle (1) in a direction of travel (5) of the motor vehicle (1); - determining (S4) a time (17) at which a measure (19) of the second driver assistance system (9) is to be carried out in order to at least counteract the collision of the motor vehicle (1) with the object (2), by evaluating the environmental data (13), wherein, if the information on unfitness to drive (16) has been transmitted, the determined time (17) is before a normal time (18) which is provided for the fit driver according to the second driver assistance system (9); - at the latest at the determined time (17), carrying out (S6) the measure (19) by means of the second driver assistance system (9).

Description

[0001] The invention relates to a method for operating a motor vehicle in which two driver assistance systems are activated. Furthermore, the invention relates to a motor vehicle configured to carry out such a method.

[0002] A motor vehicle can have at least one driver assistance system configured to control the longitudinal and / or lateral guidance of the motor vehicle. An example of such a driver assistance system is an emergency stop system, which can take at least one of several possible measures upon detecting that a driver of the motor vehicle is unfit to drive. The available measures range from a warning in the vehicle interior to a forced emergency stop of the motor vehicle. During an emergency stop, the driver assistance system can automatically brake the motor vehicle to a standstill.

[0003] DE 10 2016 203 021 A1 describes a driver assistance system with an emergency stop function for a motor vehicle. A reaction to an operation of a control element in the motor vehicle can be detected and, based on this, a driver's current status can be determined. Depending on the operation of the control element, activation of the emergency stop function can be prevented or an already activated emergency stop function can be canceled.

[0004] Furthermore, a driver assistance system can be provided in the motor vehicle, which is designed to at least counteract a collision of the motor vehicle with an object located in front of the motor vehicle in a direction of travel of the motor vehicle, such as a collision avoidance system. This driver assistance system can typically also bring about an emergency stop of the motor vehicle, which can alternatively be referred to as emergency braking. However, it is typically designed for a fit driver, i.e., it considers and / or expects a manual control input from the driver regarding the longitudinal and / or lateral guidance of the motor vehicle.

[0005] DE 10 2012 216 386 A1 describes a method for operating a driver assistance system in which a distance between the vehicle and an object in the vehicle's surroundings is determined using video data and a collision-related threshold is calculated. Depending on the calculated threshold, an action of the driver assistance system can be performed.

[0006] DE 10 2007 060 862 A1 discloses an emergency braking assistance system for a first vehicle, in which the time until a collision between the first vehicle and a second vehicle traveling ahead is approximately determined, and the determined time is compared with a lane change time and / or a circular path avoidance time and an emergency braking time. If the lane change time is shortened, a first driver warning is triggered; if the circular path avoidance time is shortened, a second driver warning is triggered; and if the emergency braking time is shortened, a third driver warning is triggered.

[0007] DE 10 2012 112 801 A1 shows a method for operating a driver assistance system of a vehicle, in which a driver state is determined by means of a driver state recognition unit and, in addition, a time period until a last possible avoidance of an object is determined depending on the determined driver state.

[0008] DE 10 2019 219 367 A1 describes a method for controlling a collision of an ego vehicle during a collision. This method can access information about an environment and objects located therein, and / or a driver state, and / or driving and vehicle parameters.

[0009] DE 10 2014 006 261 A1 describes a method for defusing an emergency situation in a moving motor vehicle. The emergency situation is detected in particular when a hands-off detection indicates that a driver of the motor vehicle is not keeping a hand on the steering wheel and that the driver does not place a hand on the steering wheel even after being requested once or repeatedly.

[0010] The various driver assistance systems of the motor vehicle typically control the longitudinal and / or lateral guidance of the motor vehicle independently of one another.

[0011] It is the object of the invention to provide a solution by means of which a driver assistance system for a motor vehicle is improved, which is designed to at least counteract a collision of the motor vehicle with an object arranged in front of the motor vehicle in a direction of travel of the motor vehicle.

[0012] The problem is solved by the subject matter of the independent and co-ordinate patent claims. Advantageous embodiments with expedient and non-trivial refinements of the invention are specified in the dependent claims, the following description, and the figures.

[0013] A first aspect of the invention relates to a method for operating a motor vehicle. Two driver assistance systems are activated in the motor vehicle. The two driver assistance systems are different from one another. The two driver assistance systems therefore differ from one another in a driver assistance system function provided by the respective driver assistance system. Generally speaking, a driver assistance system is an additional electronic device in the motor vehicle for supporting a driver of the motor vehicle in certain driving situations. Typically, a driver assistance system can control a longitudinal and / or lateral guidance system of the motor vehicle.The driver assistance system is typically provided by a control device of the motor vehicle, which in turn can provide at least one control command for, for example, a steering system of the motor vehicle, i.e., the lateral guidance, on the one hand, and / or a braking system and / or a drive device of the motor vehicle, i.e., the longitudinal guidance, on the other hand. Due to the activated driver assistance systems, the motor vehicle is configured at least for assisted driving, i.e., for example, for at least partially automated driving.

[0014] The invention is based on the finding that a driver assistance system in a motor vehicle which is designed to at least counteract a collision of the motor vehicle with an object located in front of the motor vehicle in a direction of travel of the motor vehicle, for example a collision avoidance system, always assumes that the driver is currently fit to drive. The driver assistance system therefore takes into account a possible manual control input from the driver on the longitudinal and / or lateral guidance of the motor vehicle and / or possibly even expects this. A measure carried out by the driver assistance system is therefore initially weak in terms of its field of action and its influence on the longitudinal and / or lateral guidance of the motor vehicle and can, for example, merely aim to alert the driver to the possible collision.Only if the driver fails to react, or if there are signs that indicate that the driver will not react or at least will not react in time, does the driver assistance system intensify its measures and can, for example, perform emergency braking of the vehicle. Such a sign could be, for example, an overlap of the vehicle with the object in a direction transverse to the direction of travel of the vehicle, since the overlap can be used to determine whether or not the driver intends to avoid and / or overtake the object.

[0015] When selecting the appropriate driver assistance system measure, however, it should be taken into account whether the driver is currently fit to drive. This is because if the driver is unfit to drive, manual control input from the driver to the longitudinal and / or lateral guidance of the vehicle is unlikely, or at least less likely than with a fit driver. For this reason, the driver assistance system measure should be adapted for an unfit driver and preferably more stringent than a measure that would be appropriate for a fit driver. Furthermore, the driver assistance system requires information as to whether the driver is fit or unfit to drive. For this purpose, the driver assistance system can be supported by another driver assistance system, such as an emergency stop system, which is based on this information and can therefore provide it.

[0016] The method according to the invention comprises the following steps: In one method step, environmental data and driver state data are provided. The environmental data describe an environment of the motor vehicle. The driver state data describe a state of the driver of the motor vehicle. The environmental data and the driver state data are provided in the motor vehicle. For this purpose, the environmental data and / or the driver state data can be acquired by a sensor device of the motor vehicle. The environmental data can be acquired, for example, by a camera device of the motor vehicle, which has at least one camera. The camera can be a front camera, a side camera and / or a rear camera of the motor vehicle. Furthermore, the environmental data can be provided by a radar device, a LIDAR device (LIDAR for “light detection and ranging”), an ultrasonic sensor and / or an infrared sensor as a sensor device.The surroundings of the motor vehicle can be spatially delimited by a spatial limitation of a detection range of the sensor device. The driver status data can be captured, for example, by an interior camera of the motor vehicle, which is arranged in a vehicle interior of the motor vehicle. The interior camera can alternatively be referred to as a driver monitoring camera. Alternatively or additionally, the driver status data can be provided by means of a touch sensor in a steering wheel of the motor vehicle and / or a device in the motor vehicle that captures at least one vital sign of the driver of the motor vehicle. It is preferably provided that sensor data captured in the motor vehicle itself is provided as environmental data and driver status data.

[0017] Alternatively or in addition to the acquisition of environmental data and / or driver status data in the motor vehicle, these can be provided by an external device. For this purpose, for example, the environmental data and / or driver status data can be acquired by at least one other motor vehicle and / or an infrastructure device, such as a traffic monitoring camera, and transmitted to the motor vehicle via a wireless communication connection. The external device is then, for example, the at least one other motor vehicle (vehicle-to-vehicle communication), the infrastructure device (vehicle-to-infrastructure communication), and / or an external computing device (vehicle-to-infrastructure communication) to which the environmental data was provided.In principle, the driver status data can be provided by the other motor vehicle and / or the infrastructure facility if they can record the driver in the motor vehicle, for example using a camera.

[0018] In a further method step, a first driver assistance system, which is activated in the motor vehicle and is designed, for example, as an emergency stop system, checks whether the driver of the motor vehicle is fit or unfit to drive. In other words, a check is carried out to determine which of the two predetermined states, "fit to drive" and "unfit to drive," the driver currently has. The check is performed by evaluating the provided driver state data. For example, a determination of fitness to drive that is typical for the emergency stop system can be used. For example, camera data describing at least one area of ​​the driver's eyes can be evaluated in order to monitor the driver's blinking. If the eyelid remains continuously closed, it can be concluded, for example, that the driver is unfit to drive due to a sleep phase and / or a phase of unconsciousness.Inability to drive refers to the driver's inability to operate the motor vehicle safely at the current time. This condition can depend on the situation, for example due to the consumption of medication or drugs on the one hand and / or fatigue on the other. In other words, inability to drive is a limitation of the driver's ability to operate the motor vehicle safely. A fit driver, on the other hand, is, for example, fully conscious. A fit driver is mentally capable of steering the motor vehicle manually or, for example, if a driver assistance system is activated, of taking over manual control of the motor vehicle at any time. The first driver assistance system is designed at least to partially or completely take over the longitudinal control of the motor vehicle.The first driver assistance system can be designed as an emergency stop system and alternatively be referred to as Emergency Assist.

[0019] If it is determined that the driver is unfit to drive, i.e., if it is established that the driver is currently in the "unfit to drive" state, unfit to drive information describing the driver's unfitness to drive is transmitted from the first driver assistance system to a second driver assistance system activated in the motor vehicle. The first driver assistance system thus transmits the information that the driver is currently unfit to drive to another driver assistance system of the motor vehicle. The second driver assistance system therefore receives the unfit to drive information from the first driver assistance system. The transmission can take place via a wired, in particular a wired, or a wireless, in particular a wireless, communication connection between the two driver assistance systems, if these are stored in spatially separate control devices of the motor vehicle.If both driver assistance systems are stored in a common control device, the transmission takes place internally within the control device.

[0020] The second driver assistance system is designed to at least counteract a collision of the motor vehicle with an object arranged in front of the motor vehicle in a direction of travel of the motor vehicle. The second driver assistance system can be referred to as a collision avoidance system or collision mitigation system. The second driver assistance system can be designed, for example, as a driver assistance system for warning, braking, and evasive action. For example, the second driver assistance system can be an emergency braking assistant and / or an emergency evasive action system. The second driver assistance system is typically independent of the first driver assistance system, i.e. an activity of the first driver assistance system typically has no influence on an activity of the second driver assistance system, and vice versa.The second driver assistance system can be designed as a driver assistance system that can only influence the longitudinal guidance of the motor vehicle without input from the driver. Controlling the lateral guidance of the motor vehicle using the second driver assistance system may require manual steering input from the driver. Alternatively, the second driver assistance system may be designed to control both the longitudinal guidance and the lateral guidance of the motor vehicle.

[0021] In a further method step, a point in time is determined at which a measure of the second driver assistance system is to be carried out in order to at least counteract the collision of the motor vehicle with the object arranged in front of the motor vehicle in the direction of travel of the motor vehicle. In particular, it is provided to prevent the collision with the object by means of the second driver assistance system. To determine the point in time, the environmental data is evaluated. The point in time is therefore determined by evaluating the environmental data. By evaluating the environmental data, for example, a distance to the object can be determined, so that, for example, based on this distance, the point in time at which a measure of the second driver assistance system should be taken can be deduced. The measure can be a warning, for example.However, as an alternative or in addition to the warning, it is possible for the second driver assistance system to carry out at least partial braking and, in particular, emergency braking, i.e. to initiate an emergency stop of the motor vehicle.

[0022] If the information about the driver's inability to drive was transmitted, the determined time is earlier than a normal time specified by the second driver assistance system for a fit driver. In other words, the second driver assistance system is set more strictly by the information about the driver's inability to drive than it would normally be. The normal case is a situation in which the driver is assumed to be fully fit to drive. Therefore, an earlier time is ultimately determined when determining the time because the information about the driver's inability to drive was transmitted, compared to a usual activation of the second driver assistance system in which the driver is assumed to be fit to drive. For example, a warning can now be issued at a greater distance from the object than the distance at which the second driver assistance system would normally issue the warning.Analogously, partial or full braking, i.e., emergency braking, can be activated earlier and thus at a greater distance from the object than normal. The reason for this is that the driver has been classified as unfit to drive and therefore no reaction from the driver is expected. For this reason, the measures of the second driver assistance system are amplified compared to normal. This amplified action is implemented by selecting the determined time, which is earlier than normal.

[0023] In other words, the second driver assistance system is in the normal mode whenever no information about the driver's inability to drive is available. Only when the information about the driver's inability to drive has been transmitted to the second driver assistance system does it change its mode to the mode in which the determined time is earlier than the normal time. This mode can be referred to as the inability to drive mode. The normal mode can alternatively be referred to as the ability to drive mode.

[0024] The measure is carried out by the second driver assistance system at the determined time at the latest. The second driver assistance system therefore reacts to the current situation, which includes, for example, the object in front of the motor vehicle. The second driver assistance system is thus optimized for the case that the driver is unfit to drive. The second driver assistance system is therefore improved, as it previously did not take the driver's ability to drive into account. In other words, the second driver assistance system can now differentiate between two use cases that differ in that in one use case the driver can react "normally" because they are fit to drive, whereas in the second use case it is taken into account that the driver is unfit to drive and therefore at least the time at which the measure is carried out must be adapted to the driver's inability to drive.Overall, the driver assistance system is improved, which is designed to at least counteract the collision of the motor vehicle with the object arranged in front of the motor vehicle in the direction of travel of the motor vehicle.

[0025] The time may be determined depending on the action to be taken. For example, if multiple actions are possible according to the second driver assistance system, several different times may be determined, allowing a cascade-like response of the second driver assistance system to the object the motor vehicle is approaching.

[0026] In an alternative approach, instead of the time, a distance between the motor vehicle and the object located in front of the motor vehicle in the direction of travel can be determined by evaluating the environmental data using the second driver assistance system. If the information about the driver's inability to drive has been transmitted and the determined distance is less than or equal to a minimum distance, at least one measure of the second driver assistance system is implemented, wherein the minimum distance is greater than a normal minimum distance specified for a fit driver according to the second driver assistance system.

[0027] For example, the first driver assistance system may be characterized in that a braking acceleration that can be applied by the first driver assistance system is limited to a first maximum braking acceleration value. In other words, the braking acceleration with which the driver assistance system can apply a braking system of the motor vehicle can be limited. The first maximum braking acceleration value is, for example, 3.5 meters per square second. In other words, the maximum braking power that can be provided when the first driver assistance system is activated is preferably capped, so that an arbitrarily high braking acceleration cannot be specified, but only the maximum acceleration that corresponds to the maximum braking acceleration value in terms of an acceleration value.

[0028] It can then also be provided that the second driver assistance system is characterized in that the braking acceleration that can be applied by the second driver assistance system is limited to a second maximum braking acceleration value. The second maximum braking acceleration value is greater than the first maximum braking acceleration value. The second driver assistance system can therefore, for example, be designed to brake the motor vehicle more strongly and thus faster than the first driver assistance system. The second maximum braking acceleration value is, for example, 10 meters per square second.

[0029] In this case, the described method can also ensure that the measure taken by the second driver assistance system generally specifies a greater braking acceleration for the driver who is unfit to drive than a comparable measure by the first driver assistance system.Since the current situation, which includes, for example, the object located in front of the motor vehicle, is reacted to at least by means of the second driver assistance system and not only by means of the first driver assistance system, as would otherwise be expected due to the driver's inability to drive, the greater second maximum braking acceleration that the second driver assistance system can provide can be used. This means that, for example, in the case of an unconscious driver, braking can be carried out not only with an acceleration according to the small first maximum braking acceleration value, but, for example, by means of a braking acceleration that can be increased up to the second maximum braking acceleration value. This makes the automatic reaction of the motor vehicle to the possible collision of the motor vehicle with the object particularly reliable when the driver is incapacitated, since the comparatively increased braking acceleration is possible.

[0030] The invention also includes further developments, hereinafter referred to as embodiments, which result in additional advantages.

[0031] An advantageous embodiment provides that the measure carried out by the second driver assistance system is at least one of the following measures: a distance warning, a cross-traffic warning, a pre-warning, an acute warning, preparing a braking system of the motor vehicle, activating a hydraulic brake assist system, partial braking, emergency braking and / or emergency evasive maneuvers. The measure carried out by the second motor vehicle can therefore range from a warning issued, for example, acoustically and / or visually in the motor vehicle, to preparatory steps for activating the braking system and the actual braking of the motor vehicle. The warning can be issued acoustically in the motor vehicle by means of a loudspeaker device having at least one loudspeaker and / or visually by means of a display device having, for example, a screen.The various measures are activated one after the other in the order mentioned, at different times before the predicted collision with the object. At the earliest point in time, i.e. when the distance to the object is still comparably great, the first measure mentioned, which includes a warning, is carried out. At increasingly later points in time, and thus at comparatively shorter distances from the object, the other measures mentioned, i.e. the preparatory steps up to braking, are carried out. At the latest determined point in time, i.e. when the distance to the object is comparatively short, emergency braking can be carried out as the most severe measure. Alternatively or in addition to braking the vehicle, i.e. controlling the longitudinal guidance, the emergency evasive maneuver can automatically take over the steering of the vehicle, i.e. control the lateral guidance.The emergency evasive maneuver, for example, involves automatically driving past or around the object. The actions of the second driver assistance system are thus cascaded, for example. This allows the second driver assistance system to perform an appropriate action depending on the situation.

[0032] A further exemplary embodiment provides that the measure comprises emergency braking of the motor vehicle with a braking acceleration limited to a second maximum braking acceleration value that is greater than a first maximum braking acceleration value to which the braking acceleration that can be applied by means of the first driver assistance system is limited. This requires that the two driver assistance systems have different maximum braking acceleration values, as exemplified above. Thus, instead of, for example, a mere warning or preparation of the braking system, a braking acceleration can be directly specified for the braking system of the motor vehicle, i.e., the longitudinal guidance of the motor vehicle can be controlled until it comes to a standstill. The braking system has at least one brake that is assigned to a wheel of the motor vehicle and is designed, for example, as a hydraulic brake or electronic brake.The specified braking acceleration can be the maximum braking acceleration, meaning the applied braking acceleration value can correspond to the second maximum braking acceleration value. The idea here is that a driver already classified as unfit to drive is very unlikely to react independently before colliding with the object, so it makes sense to fully automatically brake the vehicle to a standstill as quickly as possible using the second driver assistance system, i.e., to perform emergency braking. This ensures that the vehicle is reliably and as quickly as possible when the driver is unfit to drive.

[0033] Alternatively or additionally, the emergency braking can initially begin with a small braking acceleration, which can be increased, if necessary, up to the second maximum braking acceleration value. Therefore, braking does not always have to be performed with the maximum possible braking acceleration; instead, a suitable braking acceleration can be selected, which the second driver assistance system specifies to the braking system, depending on the determined time and the moment the measure is carried out.

[0034] Furthermore, one embodiment provides that the time is determined depending on the current speed of the motor vehicle. Thus, not only the environmental data can be taken into account, but also current vehicle data describing the current speed of the motor vehicle. The speed can be determined using a speed measuring device of the motor vehicle. Furthermore, based on the environmental data, the speed of the object can be estimated, for example, if this is another road user, such as a motor vehicle traveling ahead, a bicycle, and / or a pedestrian. This ultimately allows the time for the respective measure to be determined particularly reliably.

[0035] In addition, one embodiment provides that the second driver assistance system takes into account an overlap between the motor vehicle and the object in a direction transverse to the direction of travel. At least the normal time depends on overlap data that describe the overlap. Furthermore, the determined time can be dependent on the overlap data. The overlap is not to be understood in the direction of travel but only in the transverse direction. The overlap can therefore also exist if the motor vehicle is arranged at a distance of greater than 0 meters from the object. If the motor vehicle is arranged behind the object without being at least partially offset laterally, i.e. in the transverse direction, from it, there is a 100 percent overlap.If the vehicle protrudes laterally from the object and thus only partially overlaps it in the transverse direction, the overlap is between greater than 0 percent and less than 100 percent. If the vehicle is positioned transversely next to the object without any overlap, the overlap is either zero or zero percent.

[0036] The consideration of overlap is based on the realization that with a 100 percent overlap between the motor vehicle and the object, it is less likely that a fit driver will manually intervene in the control of the motor vehicle in time to avoid the object or stop the vehicle in front of it than with a smaller overlap between 0 percent and, for example, 50 percent. An overlap smaller than 100 percent typically indicates that the driver has already manually caused the motor vehicle to pivot relative to the object, indicating that they have already begun to overtake or avoid the object.In normal mode, the second driver assistance system can therefore be configured so that, for example, with an overlap of only 20 to 30 percent between the vehicle and the object, the second driver assistance system only initiates emergency braking one second before a potential collision, whereas with a 90 to 100 percent overlap, the second driver assistance system would initiate emergency braking 1.5 or 2 seconds before the potential collision. This essentially provides a particularly convenient second driver assistance system that is also pleasant to use for a driver driving in a sporty manner or driving close to the object. This is because the driver is not repeatedly and unnecessarily affected by a measure of the second driver assistance system, even though they already intend to react manually to the approaching object.In other words, this makes the second driver assistance system particularly robust, since the probability of a driver assistance system action that the driver might perceive as unnecessary, such as an improper braking of the vehicle, is relatively low. By taking the overlap into account, the normal time is determined particularly reliably.

[0037] It may be provided that the overlap is not taken into account when determining the time. This results, for example, in a typical cascade of measures provided by the second driver assistance system for normal mode being adapted in such a way that the longitudinal and / or lateral guidance is immediately activated as a measure, without, for example, a purely warning measure and / or a measure that merely prepares for intervention in the longitudinal and / or lateral guidance being implemented beforehand as an individual measure of the driver assistance system.

[0038] Alternatively, it may be possible to also consider the overlap data when determining the time. This may be useful, for example, whenever the incapacitated driver becomes fit to drive again, for example, after waking up from a sleep phase. It may then be useful to anticipate a possible reaction from the driver and therefore consider the overlap data.

[0039] According to a further exemplary embodiment, if the information regarding driving incompetence is determined, at least one measure of the first driver assistance system is carried out before the determined time. The measure of the first driver assistance system can be dependent on the acquired driver status data. The first driver assistance system can, for example, also provide several measures in a cascade manner and thus distinguish between different measure levels. The measures of the first driver assistance system can include braking of the motor vehicle, which can range from a slight braking deceleration through a medium braking deceleration to a strong braking deceleration. Furthermore, visual and / or acoustic warnings or other displays can be output in the motor vehicle.Furthermore, the first driver assistance system can automatically control the lateral guidance of the motor vehicle in addition to or as an alternative to longitudinal guidance, so that, for example, an emergency trajectory to the edge of the road can be controlled at least partially automatically and preferably fully automatically by means of the first driver assistance system. Furthermore, a distance from a motor vehicle traveling ahead can be maintained, a seat belt can be tensioned, the braking system can be prepared or a hydraulic brake assistant can be activated, hazard warning lights can be activated, and / or a vehicle horn can be sounded. In summary, the measures of the first driver assistance system include warnings and / or notifications as well as actual interventions in the longitudinal and / or lateral guidance of the motor vehicle.

[0040] If, for example, due to the position of the object relative to the motor vehicle, braking of the motor vehicle with the braking acceleration according to the second maximum braking acceleration value is not yet necessary, the measure of the first driver assistance system can be used, which is, for example, carried out first. This measure can, for example, have the effect of waking the driver, who is currently asleep, and can therefore be a sensible first measure before, for example, braking of the motor vehicle according to a measure of the second driver assistance system is carried out. This always enables the motor vehicle to be controlled while taking into account the driver's inability to drive.

[0041] Alternatively, one embodiment provides that, if the information about the driver's inability to drive is transmitted, only the measure according to the second driver assistance system is implemented. Thus, full control of the longitudinal guidance according to the second driver assistance system can be used if the driver is incapable of driving. This provides a particularly reliable response to the driver's inability to drive.

[0042] Alternatively or additionally, if the driving incapacity information is transmitted, both driver assistance systems may remain activated, and the measure of the driver assistance system with higher priority information than a comparable measure of the other driver assistance system is implemented. Alternatively or additionally, the priority information may be assigned to the respective driver assistance system, so that the measure of the driver assistance system with higher priority information is implemented. The priority information describes a priority with which the measure itself or a measure of the driver assistance system is to be implemented to avoid the collision.If, for example, the measure involves braking the motor vehicle to a standstill, the measure of the second driver assistance system can have higher priority information compared to the first driver assistance system and thus, for example, be braked with the second maximum braking acceleration. Alternatively or additionally, the measures of the second driver assistance system can generally be prioritized, i.e., always carried out instead of a measure of the first driver assistance system if the second driver assistance system has higher priority information compared to the first driver assistance system, or vice versa.

[0043] Furthermore, one embodiment provides that both driver assistance systems are overridden by the driver in the event of manual intervention. Neither the first driver assistance system nor the second driver assistance system can thus dominate a manual intervention by the driver, i.e., control the motor vehicle unaffected by the manual intervention. If, for example, the driver regains consciousness or is not incapacitated (for example, in connection with an incorrect determination or an incorrect triggering of the transmission of the incapacitated information), the driver can always counteract the measures of the respective driver assistance system. The driver can therefore regain full control of the motor vehicle at any time during the procedure.This is particularly convenient for the driver, so that, for example, after a short sleep, they can immediately take the measures they consider appropriate and are not dominated by one of the driver assistance systems.

[0044] A further aspect of the invention relates to a motor vehicle with a control device. The motor vehicle is designed to carry out the method described above. The motor vehicle according to the invention is preferably configured as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle. The invention also includes developments of the motor vehicle according to the invention that have features as have already been described in connection with the developments of the method according to the invention, i.e. in the exemplary embodiments. For this reason, the corresponding developments of the motor vehicle according to the invention are not described again here.

[0045] The invention also includes the control device for the motor vehicle. The control device can have a data processing device or a processor device configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). Furthermore, the processor device can have program code configured to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device.

[0046] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each have a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0047] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 a schematic representation of a road with several motor vehicles; and Fig. 2 shows a schematic representation of a signal flow graph of a method for operating a motor vehicle in which two driver assistance systems are activated.

[0048] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0049] In the figures, the same reference symbols denote elements with the same function.

[0050] In Fig. 1 shows a sketch of a motor vehicle 1. The motor vehicle 1 is traveling behind another vehicle, referred to here as object 2, in a lane 3 of a road 4. Both the motor vehicle 1 and the object 2 are traveling in a direction of travel 5 on the road 4. Furthermore, an oncoming vehicle 6 is traveling on the road 4. Due to the oncoming vehicle 6, for example, it is currently not possible for the motor vehicle 1 to evade the object 2, i.e. to drive around or overtake the object 2, since this could then result in a collision with the oncoming vehicle 6. The motor vehicle 1 is sketched in two different positions, with the motor vehicle 1' showing a position in which the motor vehicle 1 is offset from the object 2 in a transverse direction (y-direction) to the direction of travel 5 (x-direction).

[0051] The motor vehicle 1 has a control device 7. A first driver assistance system 8 and a second driver assistance system 9 are stored in the control device 7. The first driver assistance system 8 is, for example, an emergency stop system. The second driver assistance system 9 can be a collision avoidance system, i.e., a collision avoidance system. The second driver assistance system 9 can then be configured, for example, to control a distance from the object 2 traveling ahead and can be referred to, for example, as a "warn, brake, evade" (WBA) system. Currently, both driver assistance systems 8, 9 are activated in the motor vehicle 1.

[0052] The motor vehicle 1, for example, has several sensor devices. The sensor devices here are a front camera 10 and two lateral radar devices 11 arranged in a front area of ​​the motor vehicle 1. By means of these, the surroundings of the motor vehicle 1 can be detected. The surroundings are delimited by a detection range of the respective sensor device. The sensor devices mentioned are not exhaustive and are mentioned purely as examples. The motor vehicle 1 can have alternative or additional sensor devices, for example on the sides and / or at a rear of the motor vehicle 1.

[0053] In Fig. 1 also shows an overlap 12 between motor vehicle 1 and object 2, as well as an overlap 12' between motor vehicle 1' and object 2. This makes it clear that motor vehicle 1' only partially overlaps object 2, whereas motor vehicle 1 completely overlaps object 2. In other words, motor vehicle 1 is traveling directly behind object 2, whereas motor vehicle 1' is traveling offset in the transverse direction from object 2 and thus has a smaller overlap 12' compared to overlap 12.

[0054] In Fig. 1 also shows a current distance 20 between the motor vehicle 1 and the object 2, or a current distance 20' between the motor vehicle 1' and the object 2. The distance 20, 20' is, for example, a latest distance 20, 20' at which, given a current speed of the motor vehicle 1, 1' and the object 2, an emergency braking maneuver, i.e., automatic emergency braking, would have to be initiated by the second driver assistance system 9 in order to avoid a collision with the object 2. This makes it clear that the second driver assistance system 9 typically only needs to react at a smaller distance 20' compared to the distance 20 in the case of a smaller overlap 12', as is the case for the motor vehicle 1', than it would have to react in the case of a larger overlap 12, as is the case for the motor vehicle 1.The reason for this is that the second driver assistance system 9, in normal mode, assumes that a partial swerving maneuver that has already occurred, leading to the smaller overlap 12', indicates that a driver of the motor vehicle 1' is planning an evasive maneuver, for example, overtaking object 2, and is about to initiate this maneuver manually and, for example, is merely driving close to object 2. In the case of a larger overlap 12, on the other hand, it is assumed that the driver will not react, for example, because they fail to do so due to inattention, so that in this case, the second driver assistance system 9 should react earlier, i.e. at a comparatively greater distance 20, than in the case of the smaller overlap 12'.

[0055] With a small overlap 12, it is assumed that a small steering action of the driver is sufficient compared to a steering action with a larger overlap 12, for example, to drive the motor vehicle around the object 2 and thereby avoid the collision. A measure 19 (see reference numeral 19 in Fig. 2) of the second driver assistance system 9, at least in normal mode, is not based on the assumption that the driver will not react in the case of 100 percent overlap 12, but rather on the assumption that a necessary manual intervention by the capable driver is to be expected to avoid the collision. With the small overlap 12, a small manual intervention is sufficient, so that more time remains until the latest time at which the measure 19 of the second driver assistance system 9 must be implemented to avoid the collision, compared to the larger overlap 12.

[0056] In Fig. Figure 2 outlines a method for operating the motor vehicle 1 with the two activated driver assistance systems 8, 9. In a first method step S1, environmental data 13 is provided, here from the front camera 10 and the radar device 11 of the motor vehicle 1. The environmental data 13 describes the environment of the motor vehicle 1. Driver state data 14 is also provided, which describes a state of the driver of the motor vehicle 1. The driver state data 14 is provided here, for example, by means of an interior camera 15 of the motor vehicle 1. Thus, the environment of the motor vehicle 1 and the driver of the motor vehicle 1 are recorded.

[0057] In a method step S2, a check is performed using the first driver assistance system 8. The first driver assistance system 8 is, for example, the emergency stop system of the motor vehicle 1. It is checked whether the driver of the motor vehicle 1 is fit or unfit to drive. For this purpose, the driver status data 14 are evaluated.

[0058] If it is determined that the driver is unfit to drive, in a method step S3, an item of unfitness to drive information 16 describing the driver's unfitness to drive is transmitted from the first driver assistance system 8 to the second driver assistance system 9. The second driver assistance system 9 is also activated in the motor vehicle 1.

[0059] In a method step S4, a time 17 can then be determined at which the measure 19 of the second driver assistance system 9 would have to be carried out in order to at least counteract a collision of the motor vehicle 1 with the object 2 arranged in front of the motor vehicle 1 in the direction of travel 5. The time 17 is determined by evaluating the environmental data 13. A current speed of the motor vehicle 1 can be taken into account. Furthermore, based on the environmental data 13, for example, the speed of the object 2 can be determined if the object 2 is currently moving. If the unfitness to drive information 16 has been determined, the determined time 17 is before a normal time 18 that would be determined according to the second driver assistance system 9 for a fit driver. The determined time 17 is thus earlier than the normal time 18.

[0060] The determined time 17 can be specified as a time difference from a current time and / or as an absolute time, for example as a time of day. The determined time 17 is preferably specified as a relative time specification, so that it describes, for example, a number of seconds or milliseconds after which the collision with the object 2 is to be expected. At least the normal time 18 is typically dependent on the overlap 12. It can be provided that the overlap 12, 12' is taken into account when determining the time 17. Preferably, the overlap 12, 12' is only taken into account when determining the normal time 18, whereas when determining the determined time 17 it is not assumed that the driver could still intervene or react in time, so that the overlap 12, 12' can be ignored.

[0061] In a method step S5, it is checked whether time 17 has already been reached. At the latest at the determined time 17, action 19 of the second driver assistance system 9 is carried out in a method step S6. Action 19 can be, for example, a distance warning, a cross-traffic warning, a pre-warning, an acute warning, a preparation of the braking system of the motor vehicle 1, an activation of a hydraulic brake assistant of the motor vehicle 1, a partial braking, an emergency braking (i.e., a full braking to a standstill), and / or an emergency evasive maneuver.

[0062] For the first driver assistance system 8, it can be provided that it can only apply a braking acceleration to a braking system of the motor vehicle 1, which can be limited to a first maximum braking acceleration value. This is, for example, 3.5 meters per square second. It can also be provided that the second driver assistance system 9 provides a braking acceleration, i.e., the braking system of the motor vehicle 1 can be subjected to a braking acceleration that can be limited by a second maximum braking acceleration value. The second maximum braking acceleration value is greater than the first maximum braking acceleration value. The second maximum braking acceleration value is, for example, 10 meters per square second.Preferably, when the determined time 17 is reached, an emergency braking of the motor vehicle 1 is performed with the braking acceleration according to the second maximum braking acceleration value. The emergency braking is the emergency stop of the motor vehicle 1.

[0063] It can further be provided for the second driver assistance system 9 that it cannot control the lateral guidance of the motor vehicle 1 without a manual contribution from the driver. Thus, only interventions in the longitudinal guidance of the motor vehicle 1 are automatically possible by means of the second driver assistance system 9, for example.

[0064] If the determined time 17 has not yet been reached, at least one measure 19 of the first driver assistance system 8 can be carried out in a method step S7. Thus, for example, the strong braking acceleration according to the second driver assistance system 9 cannot yet be used, but rather, for example, the comparatively smaller braking acceleration and / or another measure 19 designed for the unfit driver, which can, for example, specify lateral guidance of the motor vehicle 1. Alternatively, it can be provided that, instead of method step S7, only the measure 19 according to the second driver assistance system 9 is always carried out.

[0065] If it was determined in method step S2 that the driver is fit to drive, the motor vehicle 1 can be operated with the second driver assistance system 9 in normal mode in a method step S8, in which, for example, the measure 19 of the second driver assistance system 9 is carried out at the normal time 18, which is later than the determined time 17.

[0066] In general, it is intended that both driver assistance systems 8, 9 can be overridden at any time by manual intervention by the driver, i.e. they no longer intervene in the longitudinal or lateral guidance of the motor vehicle 1 as soon as the driver manually specifies a control command for the longitudinal and / or lateral guidance.

[0067] Any steps performed by the driver assistance systems 8, 9, i.e. the method steps S2 to S9, are preferably performed by means of the control device 7 of the motor vehicle 1.

[0068] Overall, the examples show an adaptation of the second driver assistance system 9, which can be referred to as WBA for "warn, brake, evade," in particular the braking intervention of the second driver assistance system 9, taking into account a status of the first driver assistance system 8. If the first driver assistance system 8 determines that the driver is no longer able to react, for example because they have lost consciousness or entered a micro-sleep phase, a braking intervention of the second driver assistance system 9 takes place at an earlier determined time 17 compared to the state in which the first driver assistance system 8 is not activated, i.e., the driving incapacity information 16 was not transmitted. In other words, the determined time 17 is temporally earlier than the normal time 18.The collision with object 2 could be prevented by this additional braking intervention of the second driver assistance system 9. It is therefore assumed here that emergency braking is preferably performed as measure 19 of the second driver assistance system 9, i.e., a braking acceleration according to the second maximum braking acceleration value is preferably specified.

Claims

[1] Method for operating a motor vehicle (1) in which two driver assistance systems (8, 9) are activated, the method comprising the following steps: - Providing (S1) in the motor vehicle (1) environmental data (13) describing an environment of the motor vehicle (1) and driver state data (14) describing a state of a driver of the motor vehicle (1); - checking (S2) by means of a first driver assistance system (8) of the two driver assistance systems (8, 9) activated in the motor vehicle (1) whether the driver of the motor vehicle (1) is fit to drive or unfit to drive by evaluating the driver status data (14), wherein the first driver assistance system (8) is at least designed to partially or completely assume longitudinal guidance of the motor vehicle (1); - if it is determined that the driver is unfit to drive; transmitting (S3) an item of unfitness to drive information (16) describing the driver's unfitness to drive from the first driver assistance system (8) to a second driver assistance system (9) of the two driver assistance systems (8, 9) activated in the motor vehicle (1), wherein the second driver assistance system is designed to at least counteract a collision of the motor vehicle (1) with an object (2) arranged in front of the motor vehicle (1) in a direction of travel (5) of the motor vehicle (1); - determining (S4) a time (17) at which a measure (19) of the second driver assistance system (9) is to be carried out in order to at least counteract the collision of the motor vehicle (1) with the object (2), by evaluating the environmental data (13), wherein, if the information on unfitness to drive (16) has been transmitted, the determined time (17) is before a normal time (18) which is provided for the fit driver according to the second driver assistance system (9); - at the latest at the determined time (17), carrying out (S6) the measure (19) by means of the second driver assistance system (9). [2] Method according to claim 1, wherein the measure (19) carried out is at least one of the following measures (19): - a distance warning; - a cross traffic warning; - a warning; - an acute warning; - preparing a braking system of the motor vehicle (1); - activating a hydraulic brake assistant of the motor vehicle (1); - partial braking; - an emergency braking; and / or - an emergency evasive maneuver. [3] Method according to one of the preceding claims, wherein the measure (19) comprises an emergency braking of the motor vehicle (1) with a braking acceleration which is limited to a second maximum braking acceleration value which is greater than a first maximum braking acceleration value to which the braking acceleration which can be applied by means of the first driver assistance system (8) is limited. [4] Method according to one of the preceding claims, wherein the time (17) is determined as a function of a current speed of the motor vehicle (1). [5] Method according to one of the preceding claims, wherein the second driver assistance system (9) takes into account an overlap (12) between the motor vehicle (1) and the object (2) in a transverse direction to the direction of travel (5) and at least the normal time (18) is predetermined as a function of overlap data describing the overlap (12). [6] Method according to one of the preceding claims, wherein, if the driving incapacity information (16) is transmitted, at least one measure (19) of the first driver assistance system (8) is carried out (S7) before the determined time (17), which measure is in particular dependent on the detected driver status data (14). [7] Method according to one of claims 1 to 5, wherein, if the driving incapacity information (16) is transmitted, only the measure (19) according to the second driver assistance system (9) is carried out. [8] Method according to one of the preceding claims, wherein both driver assistance systems (8, 9) are overridden by the driver in the event of manual intervention by the driver. [9] Motor vehicle (1) with a control device (7), wherein the motor vehicle (1) is designed to carry out a method according to one of the preceding claims.

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