Driver assistance system for autonomous driving of a motor vehicle

Abstract

Method for operating a driver assistance system (12) of a motor vehicle (10), wherein during a journey of the motor vehicle (10) at least one driving maneuver (42) is carried out by a control device (26) of the driver assistance system (12) by automatically guiding the motor vehicle (10) longitudinally and / or transversely, wherein an operating device (16) is provided which generates an intervention command (U, F) for overriding the control device (26) if it is actuated by an operator (22) monitoring the at least one driving maneuver (42),wherein an analysis device (28) of the driver assistance system (12) determines at least one monitoring step to be carried out by the operator (22) before and / or during an upcoming driving maneuver (42), and depending on the at least one monitoring step, a support measure (A, C) is carried out to assist the operator (22) in carrying out the at least one monitoring step, characterized in that depending on the at least one monitoring step, an effort value is determined which describes a temporal and / or cognitive effort of the operator (22) to completely carry out the at least one monitoring step, and the support measure (A, C) is only carried out if the effort value meets a predetermined hazard criterion, wherein a threshold value is specified and the support measure (A, C) is only carried out,if the effort value is greater than the threshold.

Description

[0001] The invention relates to a driver assistance system for a motor vehicle and a method for operating the driver assistance system. During a journey of the motor vehicle, the driver assistance system performs at least one driving maneuver by automatically guiding the motor vehicle longitudinally and / or laterally. It is assumed that an operator in the motor vehicle continues to be responsible for the driving maneuvers. Therefore, an operating device is provided via which the operator can intervene in a driving maneuver.

[0002] The automatic longitudinal and / or lateral guidance of a motor vehicle, i.e., semi- and highly automated driving functions, belong to the next generation of driver assistance systems. By definition of these levels of automation, as defined, for example, by the German Federal Highway Research Institute (BASt) and the SAE (Society of Automotive Engineers), monitoring and thus responsibility for the vehicle continues to lie with the driver.

[0003] However, thanks to improved sensor technology and analysis algorithms, these driving functions will soon include complex combinations of longitudinal and lateral maneuvers. The automated execution of these maneuvers can place a significant burden on the driver's monitoring function due to the increasing complexity of the situation, or even overwhelm them. Therefore, it may not be possible to ensure that the driver can adequately monitor the systems. To fully monitor the driving maneuver, the driver must be able to understand the driving process. During an overtaking maneuver, this may mean monitoring both the distance to the vehicle in front and to an overtaking vehicle approaching from behind in the overtaking lane. Such a dual monitoring function can overwhelm the driver and may not even be feasible under supervision.

[0004] From EP 2 048 476 A1 a driver assistance method is known in which, in order to assist a driver of a vehicle while driving along a roadway, curve data of a road curve ahead as well as road condition data of the roadway are evaluated and a recommended maximum speed is determined which allows safe driving through the curve.

[0005] From DE 10 2009 028 767 A1 a motor vehicle with an assistance function is known, wherein the assistance function is provided depending on an environmental parameter and depending on a driver condition in order to adjust the necessity and the selection of the type of output of warning / information messages.

[0006] DE 10 2006 057 744 A1 describes a dynamic speed assistant for a driver assistance system which takes the vehicle's load condition into account.

[0007] DE 10 2009 048 954 A1 describes a method and a device for automatically operating a vehicle in an autonomous driving mode that does not require any user action.

[0008] DE 102 55 436 A1 describes a driver assistance system in which the operation and information output are adapted to the workload of the driver.

[0009] DE 10 2004 043 861 A1 describes a method and a route guidance system for the route guidance of a vehicle, in which a driver is guided along a pre-planned route by graphic and / or acoustic output of guidance instructions.

[0010] DE 10 2012 214 979 A1 describes a device and a method for a traffic flow assistant for a vehicle.

[0011] US 2009 / 0 192 710 A1 describes a system for predicting a collision course.

[0012] The invention is based on the object of ensuring sufficient monitoring by an operator in the motor vehicle in a driver assistance system with partially and / or highly automated driving functions.

[0013] The problem is solved by the subject matter of the independent patent claims. Advantageous developments of the invention are disclosed in the dependent patent claims.

[0014] According to the invention, a method for operating the driver assistance system is provided, wherein, during a journey of the motor vehicle, at least one driving maneuver is carried out by a control device of the driver assistance system in a manner known per se by automatically guiding the motor vehicle longitudinally and / or laterally. To enable intervention by an operator located in the motor vehicle in the event of an undesirable course of a driving maneuver, an operating device of the driver assistance system is provided which generates an intervention command for overriding the control device, i.e., for changing the course of the driving maneuver, if the operating device is actuated by the operator monitoring the at least one driving maneuver.

[0015] To ensure that the operator is not overwhelmed in their monitoring task, the invention provides that an analysis device of the driver assistance system determines at least one monitoring step to be performed by the operator before and / or during an upcoming driving maneuver, for example an overtaking maneuver or a turning maneuver. For example, the analysis device can determine that for an upcoming overtaking maneuver, both a distance to a vehicle ahead and a minimum driving speed when changing into an overtaking lane must be ensured because another vehicle is approaching from behind in the overtaking lane. To ensure that the operator is not overwhelmed in such a situation, for example, the analysis device carries out a support measure.In other words, according to the invention, the analysis device, depending on the at least one determined monitoring step, carries out a support measure to assist the operator in carrying out the at least one monitoring step. In the example described, the operator can thus be alerted, for example, to an unfamiliar vehicle approaching from behind.

[0016] The invention offers the advantage of providing the operator with technical support to systematically and specifically carry out all necessary monitoring steps to ensure a safe journey. This saves time and ensures the complete implementation of all required monitoring steps.

[0017] To determine the upcoming driving maneuver for the described method according to the invention, maneuver planning from a driver assistance system with partially and / or highly automated driving functions can be used in a conventional manner. This indicates the next planned driving maneuver. Furthermore, an upcoming maneuver can be read additionally or alternatively from a navigation system, which can, for example, signal an upcoming turning maneuver based on a planned route.

[0018] The method according to the invention has further developments relating to the determination of the required monitoring steps mentioned. One of these embodiments provides that at least one external object likely involved in the driving maneuver, for example another road user such as another vehicle, or a stationary object such as a lamppost, is located using a vehicle sensor system. For example, a digital map with at least one object located in the vicinity of the motor vehicle is generated for this purpose. The at least one monitoring step is then determined as a function of the at least one located object. In other words, the at least one monitoring step can consist of the operator having to observe each of the located objects once. A viewing direction can be determined using a digital map.Locating objects external to the vehicle has the advantage that at least one monitoring step is adapted to the current traffic situation.

[0019] Another embodiment provides that the upcoming driving maneuver is assigned to one of several predetermined maneuver classes. For example, these maneuver classes can include: crossing an intersection, turning maneuver, overtaking with possible overtaking traffic (as may be the case on a motorway), overtaking with possible oncoming traffic (as may be the case on a country road), overtaking in a construction zone, and merging maneuver (as may be necessary on a motorway entrance ramp). If the upcoming driving maneuver is then assigned to one of the maneuver classes, there is a maneuver class for the driving maneuver. The at least one monitoring step is then assigned depending on the maneuver class of the driving maneuver. For each maneuver class, information about at least one required monitoring step can therefore be stored.For example, during an overtaking maneuver on a highway, one monitoring step might involve checking for traffic behind, and another might involve monitoring the distance to the other vehicle ahead. When crossing an intersection, a necessary monitoring step might be looking into the intersecting road, i.e., checking for cross traffic. Determining the monitoring steps based on a maneuver class has the advantage that important monitoring steps typical for the respective maneuver class can be specified with minimal sensor effort.

[0020] As already explained, the support measure can consist of providing indications of the monitoring steps to be performed. However, this can lead to the undesirable effect of the driver always first considering, for example, a visual indication and only then performing the monitoring step. This can result in a loss of time, which is particularly unnecessary if the monitoring steps are already clear to the driver in advance and the support measure is actually superfluous.

[0021] The method according to the invention provides that, depending on the at least one monitoring step, an effort value is first determined, which describes the temporal and / or cognitive effort required by the operator to fully carry out the at least one monitoring step. In other words, a hazard measure or complexity measure relating to the upcoming monitoring task is first determined. The cognitive effort can be determined, for example, as a function of the number of objects external to the vehicle in the surrounding area that the operator must observe in order to assess the current traffic situation. Once the effort value for monitoring has been determined, the support measure is only carried out if the effort value meets a predetermined hazard criterion.In addition, a threshold is specified, and the assistance measure is only implemented if the effort value exceeds the threshold. Determining the effort value has the advantage that the assistance measure is provided as needed only in driving situations where there is a risk that the operator will be overwhelmed.

[0022] According to one embodiment of the invention, the effort value is determined as a function of a total number of the monitoring steps determined.

[0023] Additionally or alternatively, an execution time required to carry out the at least one monitoring step can be determined. In this case, it is particularly preferably provided that the threshold value for the comparison is determined adaptively as a function of the current traffic situation, i.e. a time period actually available for monitoring. A measure of the available time period can, for example, be a time-to-collision (TTC) for maximum collision-free driving. The required execution time for all monitoring steps can then be compared with the available time period. If sufficient time is available, the support measure is not carried out; if, on the other hand, there is insufficient time, the support measure is carried out.

[0024] Additionally or alternatively, the effort value can also be determined depending on the body movement and / or movement sequence required to perform the at least one monitoring step. This advantageously takes into account the fact that distraction caused by body movement, such as that required for a shoulder check, can impair the operator's attention and thus lead to a loss of overview of the traffic situation.

[0025] However, factors influencing the operator's decision-making time can also be used to determine the effort value, as time can pass from the moment an object is seen to the moment a hazard is recognized, and this time can be estimated. One embodiment provides for the effort value to be determined based on a habit value relating to the operator's familiarity with the route in question. With a predetermined minimum frequency of journeys on the route, it can be assumed that the operator will assess the current traffic situation more quickly than on a route that has been traveled less frequently by the operator.

[0026] Additionally or alternatively, the effort value can also be calculated based on a reaction time value stored for the operator. This advantageously allows the operator's age, for example, to be taken into account.

[0027] Additionally or alternatively, the effort value can be determined based on the operator's vigilance signaled by an attention monitor. Attention monitoring devices are well known in connection with driver fatigue monitoring. Their signal regarding the operator's vigilance (attention) can also be advantageously used to determine the effort value.

[0028] The effort value can be calculated depending on the aforementioned variables, for example, using a calculation formula that can be determined through simple experiments. However, one embodiment provides that the effort value is determined using a digital mental model of the operator. Such mental models are known per se in connection with ergonomic considerations of operating devices. These can also be advantageously used to operate the driver assistance system according to the invention. The mental model is preferably trained during the journey depending on the operator's behavior. This adapts the mental model to the operator.

[0029] As already described in connection with the TTC, the checked hazard criterion is preferably adapted to the current driving situation. One embodiment of the method provides for this purpose that a hazard value is determined by the analysis device depending on object data for at least one external object located in the surroundings of the motor vehicle, and the hazard criterion includes that the described effort value is greater than the hazard value. For example, the monitoring time available for carrying out the monitoring steps can be determined as the effort value and then compared with a required implementation time for the at least one monitoring step as the hazard value. According to one embodiment, the hazard value is determined depending on a TTC value determined by a collision warning system of the motor vehicle.

[0030] However, the time available is not necessarily the only decisive factor. In a complex situation, an operator may be able to perform a monitoring step in a timely manner; however, this does not guarantee that the operator has actually mentally perceived everything. Therefore, in addition to or as an alternative to this, the danger value is determined based on a visibility value that describes the current visibility conditions. This takes into account, for example, the reduced visibility during night driving or in fog or rain.

[0031] Additionally or alternatively, the hazard value can be determined based on the current and / or planned driving speed for the upcoming maneuver. This takes into account the rate of change of the driving situation, i.e., its dynamics, and the resulting increased demands on the operator's reaction speed.

[0032] Additionally or alternatively, the hazard value can be determined based on at least one distance value and / or relative speed value to a respective external object. This advantageously takes into account the fact that after detecting a hazard, the operator still has sufficient reaction time to activate the control device. A fixed, predetermined value, which can be determined in simple reaction tests, can be used as the reaction time.

[0033] The invention provides further embodiments depending on how the support measure is designed.

[0034] According to one embodiment, as a support measure, the upcoming driving maneuver is delayed, i.e., carried out at a later time. This gives the operator more time to perform the monitoring steps. Additionally or alternatively, the driving speed of the motor vehicle is reduced. This reduces the temporal dynamics, i.e., the rate of change in the driving situation, making it clearer for the operator. Another embodiment provides for waiting for a foreign vehicle to pass. This advantageously eliminates a monitoring step. A generalization of this idea provides for a maneuver modification of the upcoming driving maneuver, which reduces the number of monitoring steps to be performed.Which maneuver change is suitable can be determined in advance for some of the described maneuver classes, for example.

[0035] According to another development, as a support measure, a notification of at least one monitoring step is output to the operator, as already described. Existing or novel output elements can be used for this purpose, such as a head-up display and / or a warning light in the exterior mirror or instrument cluster and / or data glasses with augmented reality functionality, through which graphic information is displayed in the operator's field of vision, with the graphic information being superimposed on the real image impressions.

[0036] The previous embodiments have always been described in connection with a single, upcoming driving maneuver. However, a journey using the driver assistance system can also consist of a sequence of driving maneuvers to be performed one after the other, which are determined, for example, by the maneuver planning of the driver assistance system. According to one embodiment of the method, the driving maneuver for which the monitoring steps are determined and the corresponding support measure is implemented is determined by determining at least one further upcoming driving maneuver, i.e., at least two or more upcoming driving maneuvers are present, and from all of the upcoming driving maneuvers that have been determined, one of them is selected based on a priority criterion as the next upcoming driving maneuver for implementation of the support measure.This priority criterion takes into account the temporal proximity of the at least one monitoring step to be performed and / or the spatial proximity of external objects likely to be involved in the upcoming driving maneuver. This offers the advantage that the operator is always alerted to the nearest hazard by the support measure or is supported in monitoring this hazard.

[0037] The invention also includes a driver assistance system or a driver assistance device designed to carry out the described method according to the invention. The driver assistance system according to the invention has a control device for automatically guiding the motor vehicle longitudinally and / or laterally and an operating device for generating an intervention command for overriding the control device, depending on the operator's actions. According to the invention, the driver assistance system is equipped with an analysis device designed to determine at least one monitoring step to be performed by the operator before and / or during an impending driving maneuver and to carry out a monitoring measure that supports the at least one monitoring step. The driver assistance system according to the invention is configured to carry out an embodiment of the method according to the invention.

[0038] Finally, the invention also includes a motor vehicle characterized by an embodiment of the driver assistance system according to the invention. The motor vehicle according to the invention can be configured, for example, as a motor vehicle, such as a passenger car.

[0039] An exemplary embodiment of the invention is described below. It shows: Fig. 1 is a schematic representation of an embodiment of the motor vehicle according to the invention; and Fig. 2 a sketch of a driving situation in which an embodiment of the method according to the invention is carried out by the motor vehicle of Fig. 1 can be carried out.

[0040] The exemplary embodiment explained below is a preferred embodiment of the invention. However, in the exemplary embodiment, the described components of the embodiment each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are thus also considered components of the invention, either individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by further features of the invention already described.

[0041] In Fig. 1 shows a bird's-eye view of a motor vehicle 10, which may be, for example, a motor vehicle, in particular a passenger car. The motor vehicle 10 may have a driver assistance system (DAS) 12, a vehicle sensor system 14, an operating device 16, an actuator device 18 for driving the motor vehicle 10, and an output device 20 for outputting information to an operator 22 of the motor vehicle 10. The operator 22 may, for example, be sitting in a driver's seat 24.

[0042] The driver assistance system 12 can have a control device 26 for generating a control signal S for the actuator device 18 and an analysis device 28 for evaluating sensor data or measurement data M from the vehicle sensor system 14 and maneuver plan data P from a maneuver plan 30 of the control device 26, as well as for generating a control command C for the control device 26 and / or an output signal A for the output device 20. The control device 26 and the analysis device 28 can each be provided, for example, by a program module of a processor device, for example, a control unit of the motor vehicle 10.

[0043] The sensor device 14 can be designed to locate objects external to the vehicle and to signal the located objects by means of the measurement data M. The vehicle sensor system 14 can comprise a plurality of sensors distributed throughout the motor vehicle 10, which can be Fig. 1 is symbolized by a front sensor part 14' and a rear sensor part 14". The vehicle sensor system 14 can, for example, comprise a radar and / or a lidar and / or ultrasonic sensors and / or one or more cameras and / or a car-to-X communication device.

[0044] The operating device 16 can, for example, comprise a steering handle, such as a steering wheel or a steering stick, and / or a set of pedals. It can be provided that the operator 22 uses the operating device 16 to generate guidance commands F for longitudinal and / or transverse guidance of the motor vehicle 10, which are transmitted to the actuator device 18.

[0045] The actuator device 18 can be, for example, a drive-by-wire system. It can be designed to act on, for example, a steering linkage of the motor vehicle 10 and / or an engine control unit of the motor vehicle 10 and / or a braking system of the motor vehicle 10 by means of actuators in a manner known per se, depending on the control command S and / or the guidance command F, and thereby implement the control commands S and / or guidance commands F for the longitudinal and / or transverse guidance of the motor vehicle 10 and thereby perform the longitudinal and / or transverse guidance of the motor vehicle 10.

[0046] The display device 20 can, for example, comprise a screen of the motor vehicle 10 and / or a head-up display and / or a warning light in an exterior mirror (not shown) or an instrument cluster. The output device 20 can also comprise an audio system for outputting warning signals and / or announcements, and optionally a screen of an infotainment system of the motor vehicle 10. The output device 20 can also comprise an augmented reality system, for example, with data glasses.

[0047] In motor vehicle 10, it is possible to provide a partially automated and / or a highly automated driving mode and / or to enable assisted driving by means of the driver assistance system 12. The two driving modes differ in the periods and / or situations in which they must be fully or only partially monitored by the driver. Partially automated means, in particular, that the vehicle assumes longitudinal and lateral control (preferably only within predetermined limits) and the driver continuously monitors. Highly automated means, in particular, that the vehicle assumes longitudinal and lateral control (preferably only within predetermined limits) and the driver no longer continuously monitors, but only in predetermined driving situations. In assisted driving, a distinction is made with regard to the degree of freedom.Assisted means that the vehicle assumes either longitudinal or lateral control (preferably only within predetermined limits), and the driver continuously monitors. The respective guidance task performed by the driver assistance system 12 can be carried out by the control system 26 in a conventional manner, for example, based on the maneuver planning 30.

[0048] In the motor vehicle 10, it is provided that the operator 22 continues to be responsible for all driving maneuvers of the motor vehicle 10, i.e., including the driving maneuvers performed by the driver assistance device 12 and implemented by means of the control commands S. Therefore, it can be provided that the operator 22 can generate an override command U using the operating device 16, for example, by correcting a steering maneuver by turning a steering wheel. Likewise, an override command U for braking the motor vehicle 10 can be generated, for example, by operating a brake pedal. The override can also be implemented by means of the control commands F, in that the actuator device 18 implements the control commands F with a higher priority than the control commands S.

[0049] The maneuver planning 30 identifies and plans individual driving maneuvers during a journey of the motor vehicle 10, which are then converted into control commands S by the control device 26 in the sequence determined by the maneuver planning 30.

[0050] In Fig. 2 illustrates an exemplary driving situation 32 in which the motor vehicle 10 is traveling in a lane 34 behind a leading vehicle 36, and an overtaking vehicle 40 is approaching the motor vehicle 10 from behind in a passing lane 38. The vehicle sensor system 14 detects and locates both other vehicles 36, 40.

[0051] For example, on the basis of the measurement data M, the maneuver planning 30 then plans a driving maneuver 42 in the example, which Fig. 2 is represented by the driving trajectory of the motor vehicle 10 subsequently planned by the control device 26. In the example, the driving maneuver 42 is an overtaking maneuver.

[0052] The operator 22 is now responsible for ensuring that the motor vehicle 10 does not approach too closely to the preceding motor vehicle 36 during the driving maneuver 42, i.e., does not drive too close or, in other words, that a time-to-collision TTC1 does not fall below a prescribed value. Furthermore, the driving maneuver 42 must not result in the motor vehicle 10 merging so closely in front of the overtaking other vehicle 40 that a time gap TTC2 falls below a predetermined critical value. The calculation of a time gap is known per se from the prior art. The complexity of the driving situation 32 for the operator 22 therefore consists in ensuring a sufficiently large distance from the slower vehicle in front, as well as merging with sufficient distance from the following vehicle in the adjacent lane, i.e., the overtaking lane 38, as well as a sufficiently high driving speed.

[0053] To ensure that the operator 22 is not overwhelmed in this case, the driver assistance system provides a remedy in that the analysis device 28 determines a hazard level based, for example, on the measurement data M and the driving maneuver planning data P. This hazard level provides information about the complexity of the driving situation 32. For example, the hazard level is calculated from the lane change time gap to the vehicle behind (TTC2) and the time-to-collision TTC1 to the vehicle in front. For example, the smaller of the two time values can be used as a basis. If a predetermined safety threshold is undershot, i.e. if the combined TTC is too low, the driver assistance system 12 must initiate measures to give the operator 22 sufficient time to perceive, assess, and, if necessary, override the driver assistance system 12. The following measures may be envisaged, for example:

[0054] In the Fig. In the example illustrated in Figure 2, the driving maneuver 42, which consists of the combination of approaching the other vehicle 36 and initiating the lane change into the overtaking lane 38, can be delayed or modified by the driver assistance system 12, even though from a technical perspective it can be carried out safely and conveniently by the control device 26. For example, the lane change can be postponed to a later time after the other vehicle 40 has overtaken. This change or modification of the driving maneuver 42 can be triggered by the analysis device 28 using the control commands C, by controlling the control device 26 using the control commands C.

[0055] A second possibility is to carry out the driving maneuver 42, but to inform the operator 22 early on about all critical points, i.e., to communicate the monitoring steps necessary to ensure complete monitoring of the driving maneuver 42 by the operator 22, visually or acoustically by means of the output device 20 to the operator 22. For example, the operator 22 can be informed about the collision with the vehicle in front 36, the initiation of the lane change, and the execution of the lane change, and can be made aware of the other vehicles 36, 40 to be checked. This creates an understanding of the situation, and the operator 22 can specifically monitor several vehicles, i.e., in the example, the other vehicles 36 and 40, although they must look in different directions to do so.

[0056] The Fig.The example shown in Figure 2 can also be applied to other complex driving situations in which the operator 22 would not be able to assess the safety of the corresponding driving maneuver in a short time without prompts or appropriate modification of the driving maneuver. Such complex driving situations include, for example, overtaking in construction zones / narrow passages, and intersection and turning maneuvers.

[0057] An advantageous further development concerns the monitoring capability during obstructed visibility, such as can be caused by weather conditions and daylight. The monitoring capability of the operator 22 decreases accordingly when obstructed visibility occurs and can be taken into account when configuring the driver assistance system 12, for example, by increasing the values for TTC1 and TTC2 when visibility is reduced or impaired.

[0058] In connection with the aforementioned intersection crossing, for example, it can be provided that the automatic crossing takes place slowly so that the operator 22 can monitor the crossing traffic. An overtaking maneuver on a country road, for example, can be planned with a time buffer so that the traffic can be reliably assessed. Overtaking in construction zones can take into account the fact that a monitoring step concerning the narrow road layout on the one hand and a further monitoring step concerning the motor vehicle 10 swerving into the adjacent lane must be monitored. A turning maneuver can provide for the monitoring steps that crossing traffic must be detected, the blind spot of the rear-view mirrors must be checked by looking over the shoulder, and pedestrians must be watched for.Merging into a lane, such as a motorway entrance, can take into account the monitoring steps that the relative speed of the other vehicles must be detected, the own travel trajectory of the motor vehicle 10 must be monitored and the end of the merging lane must be kept in view.

[0059] In general, the driver assistance system 12 according to the invention can be used in all situations in which the perception and interpretation ability of the operator of the motor vehicle 10 is slower or poorer than that of the machine, i.e., the driver assistance system 12 in combination with the vehicle sensor system 14. In connection with the SAE levels for vehicle automation defined in the prior art, the states would be "Partial Automation" and "Conditional Automation".

[0060] Warnings via the output device 20 and the adaptation of the driving maneuvers via the control commands C must be based on the information processing capacity of humans, i.e. the time required for human perception and interpretation.

[0061] During a journey of the motor vehicle 10, the maneuver planning system 30 determines a continuous sequence of driving maneuvers that must be implemented in order to progress along a planned route. During the journey, the individual driving maneuvers are reviewed to determine which of the driving maneuvers requires the next corresponding instructions via the output device 20 or driving maneuver changes via the control commands C. For this purpose, the objects in the vehicle's surroundings and the current driving situations are identified with regard to the type of hazards present, for example, intersection traffic, the distances to surrounding vehicles, and the relative speeds. These hazards are then prioritized, which can include both temporal prioritization, i.e., the most acute hazard, and spatial prioritization, i.e., the closest hazard in terms of location.

[0062] The highest-priority hazard can then form the basis for a system decision by the driver assistance system 12, i.e., in particular, the analysis device 28. The decision is based on whether the operator 22 is able to assess the driving situation without any indications or interventions by the analysis device 28, or whether this is not the case. In the latter case, a decision must then be made as to whether the operator 22 should be warned or informed (output of output signals A for the output device 20) or whether the driving situation should be defused, for example, by a slower / more cautious driving maneuver (output of control commands C). Of course, these two system reactions can also be combined.

[0063] The operator 22 is then informed of the hazards by targeted, parallel / sequential output of warnings via the output device 20. The operator 22 is informed of the necessary monitoring steps, i.e., by communicating what needs to be monitored. Symbols or voice announcements can be output for this purpose. Automatically adjusting the driving style of the motor vehicle 10 can ensure that the operator 22 can recognize all hazards without additional warning and can monitor them with sufficient time.

[0064] A further possibility for parameterizing the driver assistance system 12 is to take into account the familiarity of the route, i.e. to take into account whether the operator 22 is currently driving the motor vehicle 10, for example, on the daily commute and already knows the operator 22 and the dangers to be expected there and can therefore monitor them without assistance.

[0065] Overall, the example shows how the invention can ensure monitoring of automatic driving functions by the driver.

Claims

[1] Method for operating a driver assistance system (12) of a motor vehicle (10), wherein during a journey of the motor vehicle (10) at least one driving maneuver (42) is carried out by a control device (26) of the driver assistance system (12) by automatically guiding the motor vehicle (10) longitudinally and / or transversely, wherein an operating device (16) is provided which generates an intervention command (U, F) for overriding the control device (26) if it is actuated by an operator (22) monitoring the at least one driving maneuver (42),wherein an analysis device (28) of the driver assistance system (12) determines at least one monitoring step to be carried out by the operator (22) before and / or during an upcoming driving maneuver (42) and, depending on the at least one monitoring step, a support measure (A, C) is carried out to assist the operator (22) in carrying out the at least one monitoring step, characterized bythat, depending on the at least one monitoring step, an effort value is determined which describes a temporal and / or cognitive effort of the operator (22) to completely carry out the at least one monitoring step, and the support measure (A, C) is only carried out if the effort value meets a predetermined hazard criterion, wherein a threshold value is predetermined and the support measure (A, C) is only carried out if the effort value is greater than the threshold value. [2] Method according to claim 1, wherein at least one vehicle-external object (36, 40) likely to be involved in the driving maneuver (42) is located using a vehicle sensor system (14), and the at least one monitoring step is determined as a function of the at least one located object (36, 40). [3] Method according to one of the preceding claims, wherein the upcoming driving maneuver (42) is assigned to one of several predetermined maneuver classes and the at least one monitoring step is determined as a function of the maneuver class of the driving maneuver (42). [4] Method according to one of the preceding claims, wherein the maneuver classes include: crossing an intersection, turning maneuver, overtaking with possible overtaking traffic, overtaking with possible oncoming traffic, overtaking in construction, merging maneuver. [5] Method according to claim 1, wherein the effort value is determined as a function of a number of the at least one monitoring step and / or a duration of execution required to carry out the at least one monitoring step and / or body movement and / or movement sequence. [6] Method according to one of claims 1 or 5, wherein the effort value is determined as a function of a habit value relating to the familiarity of the operator (22) with the route relating to the journey and / or a reaction time value stored for the operator (22) and / or a vigilance of the operator signalled by an attention monitoring system. [7] Method according to one of claims 1 or 5 or 6, wherein the effort value is determined by means of a digital mental model of the operator (22), wherein the mental model is preferably trained during the journey as a function of a behavior of the operator (22). [8] Method according to one of claims 1 or 5 to 7, wherein a danger value (TTC1, TTC2) is determined by the analysis device (28) as a function of object data (N) relating to at least one vehicle-external object (36, 40) located in an environment of the motor vehicle (10), and the danger criterion comprises that the effort value is greater than the danger value (TTC1, TTC2). [9] Method according to claim 8, wherein the danger value (TTC1, TTC2) is determined as a function of a TTC value (TTC1, TTC2) determined by a collision warning system of the motor vehicle (10) and / or a visibility value describing the current visibility conditions and / or a current driving speed and / or a driving speed planned for the driving maneuver and / or at least one distance value and / or relative speed value to a respective object external to the vehicle. [10] Method according to one of the preceding claims, wherein as a support measure (C) the upcoming driving maneuver (42) is delayed and / or a driving speed of the motor vehicle (10) is reduced and / or a passing of a foreign vehicle (40) is waited for and / or a maneuver change of the upcoming driving maneuver (42) is carried out, designed to reduce a number of monitoring steps to be carried out. [11] Method according to one of the preceding claims, wherein as a support measure (A) an indication of the at least one monitoring step is output to the operator (22). [12] Method according to one of the preceding claims, wherein at least one further upcoming driving maneuver is determined and from all upcoming driving maneuvers one of them is selected on the basis of a priority criterion as the next upcoming driving maneuver for carrying out the support measure, wherein the priority criterion takes into account a temporal proximity of the at least one monitoring step to be carried out in each case and / or a spatial proximity to at least one object external to the vehicle that is likely to be involved in the respective upcoming driving maneuver. [13] Driver assistance system (12) with a control device (26) for automatically guiding a motor vehicle (10) longitudinally and / or transversely and an operating device (16) for generating an intervention command (U, F) for overriding the control device (26) in a control-dependent manner, characterized bythat the driver assistance system (12) has an analysis device (28) for determining at least one monitoring step to be carried out by the operator (22) before and / or during an impending driving maneuver (42) and for carrying out a support measure (A, C) supporting the at least one monitoring step, and the driver assistance system (12) is set up to carry out a method according to one of the preceding claims. [14] Motor vehicle (10) with a driver assistance system (12) according to claim 13.

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