Driver assistance system for a motor vehicle and method for operating a driver assistance system or motor vehicle

Description

[0001] The invention relates to a driver assistance system for a motor vehicle, a corresponding motor vehicle with such a driver assistance system and a method for operating such a driver assistance system and / or motor vehicle.

[0002] Many different driver assistance systems for motor vehicles are already known today. These systems can support the driver in driving the vehicle or at least partially automate driving operations or individual driving tasks. One example of this is a brake assist or collision avoidance system, which, in emergency situations, brings the vehicle to a standstill as quickly as possible through automatic braking intervention in order to avoid a collision with a detected obstacle or to mitigate it as much as possible. However, such emergency braking interventions are typically limited to acutely dangerous situations in which strong and correspondingly uncomfortable automatic interventions in the longitudinal and / or lateral guidance of the vehicle are accepted.However, such systems have the disadvantage that they are neither error-free, for example in the detection of obstacles that justify or make emergency braking with maximum force necessary, nor are they always absolutely reliable, nor are they suitable for all traffic situations.

[0003] DE 10 2004 058 037 B4 describes a driving assistance device for preventing a vehicle collision. Targets present in front of the vehicle are detected, and a processor assists the vehicle's movement to stop the vehicle in a safe position. Given that incorrectly detected objects may lead to a braking action that does not correspond to the driver's intention, the processor is designed to stop the vehicle only if a plurality of targets in front of the vehicle are detected and these targets are of the same type.

[0004] DE 11 2015 003 634 T5 discloses a display device for a vehicle that displays various information related to the movement of a vehicle to a viewer within a display area. An outer periphery of such a display is formed by a ring section, which is visually perceived as a virtual image within the display area. The display device has a movement mechanism capable of moving a position of the ring section. A suitably equipped vehicle can, for example, have a camera for detecting an environment. The display device can then, for example, display a warning about an approaching vehicle.

[0005] US 2018 / 0151075 A1 discloses a driver assistance system for avoiding a collision with a pedestrian. This system uses vehicle surroundings data to detect a pedestrian and determine the distance between the vehicle and the pedestrian. Based on the distance and the vehicle's braking capability, depending on the current load and environmental conditions, the driver can be warned, and an automatic braking maneuver can be initiated to avoid a collision and a warning signal can be issued to warn the pedestrian.

[0006] DE 11 2006 002 248 B4 discloses a driver assistance system for brake control, in which the brake control is carried out in stages by controlling a vehicle brake and an auxiliary brake. Upon detecting an object in the direction of travel in front of the vehicle, the driver assistance system initiates braking according to a braking profile, with the braking force being increased over a number of stages in a time sequence, thus avoiding an emergency braking situation to prevent a collision with the object.

[0007] DE 10 2010 021 591 A1 discloses a plausibility monitoring module for monitoring a driver assistance system. This module regulates the limiting case at a point in time at which a semi-autonomous driver assistance system deactivates and the driver is supposed to take over control of the vehicle. If the driver fails to react, the plausibility monitoring module is configured to initiate a stopping of the vehicle according to a stored emergency braking plan, which has a braking profile with a constant, increasing, or decreasing acceleration.

[0008] DE 10 2008 056 204 A1 discloses a braking module that, upon detecting an object in front of the vehicle in the direction of travel, initiates a two-stage braking process to prevent a collision between the vehicle and the object. Upon detecting the object, a first braking stage with a reduced braking intervention is activated. Upon a certain distance to the object being exceeded, the braking pressure is increased in a second braking stage to avoid a collision.

[0009] Document US 2008 / 0167781 A1 describes how a driver assistance system in a motor vehicle can issue a haptic warning when the motor vehicle approaches an obstacle with which it is at risk of colliding. This haptic warning can be configured as a braking impulse.

[0010] The object of the present invention is to increase road safety in a particularly convenient manner. This object is achieved according to the invention by the subject matter of the independent patent claims. Advantageous embodiments and further developments of the present invention are specified in the dependent patent claims, in the description, and in the figures.

[0011] A driver assistance system according to the invention for a motor vehicle serves to assist a driver of the motor vehicle during longitudinal guidance of the motor vehicle. The driver assistance system according to the invention is configured to detect an obstacle located in front of the motor vehicle in the direction of travel based on environmental data provided by an environmental sensor system. The environmental sensor system can be part of the driver assistance system itself. The environmental sensor system can also be part of the motor vehicle, in which case the driver assistance system can have a corresponding data interface via which the environmental data provided by the environmental sensor system can be transmitted or received. The environmental sensor system and the driver assistance system can be connected or coupled to one another directly or, for example, via an on-board electrical system of the motor vehicle.The environmental sensor system can be or comprise one or more sensors, for example a camera, a radar, lidar or ultrasound device, a laser scanner and / or the like. The environmental data thus characterize the respective current environment of the motor vehicle. The driver assistance system according to the invention is further configured, according to a first functionality, to initiate an emergency braking intervention in order to bring the motor vehicle to a standstill in order to avoid an otherwise imminent collision with the detected obstacle. An emergency braking intervention in this sense can, in particular, be an automatic intervention in the longitudinal guidance of the motor vehicle, by which the maximum possible or achievable deceleration of the motor vehicle is brought about. For this purpose, the driver assistance system can, for example, transmit a corresponding control command to a braking system of the motor vehicle, which then applies the technically maximum possible braking force.This first functionality of the driver assistance system is designed to avoid or mitigate a collision between the motor vehicle and the detected obstacle in an acutely dangerous situation. Any reduced comfort for the driver or other vehicle occupants caused by the maximum braking deceleration that occurs during emergency braking intervention is given lower priority than avoiding or mitigating the collision and is therefore accepted. Emergency braking intervention therefore represents an emergency measure used as a last resort to avoid or mitigate a collision and is therefore generally not suitable for less dangerous situations that occur during normal driving.

[0012] According to the invention, the driver assistance system is further configured, according to a second functionality, to initiate a longitudinal guidance intervention that is weaker than the emergency braking intervention to slow down the motor vehicle as soon as the obstacle is detected and before the motor vehicle has approached the detected obstacle so closely that the collision can only be prevented by the emergency braking intervention. In other words, it is therefore provided that when approaching the detected obstacle, the motor vehicle is slowed down or decelerated by the weakened longitudinal guidance intervention at an earlier point in time than is conventionally provided as the start of the emergency braking intervention. The weakened longitudinal guidance intervention applies or brings about a lower or weaker deceleration, i.e. a smaller braking acceleration or deceleration in magnitude than for or during the emergency braking intervention.This is possible without danger because at the time or during the duration of the reduced longitudinal guidance intervention, the distance between the motor vehicle and the detected obstacle is still large enough to avoid the collision by means other than the emergency braking intervention.

[0013] In the present invention, the driver assistance system is configured to effect the reduced longitudinal guidance intervention only for a predetermined period of time after the obstacle has been detected and to terminate it before the motor vehicle has approached the obstacle so close that a collision with the obstacle can only be prevented by emergency braking. In other words, the reduced longitudinal guidance intervention is used only as a relatively brief, i.e. temporary, indication to the driver in order to draw their attention to the situation or the detected obstacle while they are approaching the detected obstacle. The predetermined period of time can be specified as an absolute value. The predetermined period of time, i.e. a duration of the reduced longitudinal guidance intervention, can then be, for example, at least approximately, 0.5 s.However, the specified time period can also be specified as a relative value or by a calculation rule.

[0014] The actual time period or duration of the reduced longitudinal guidance intervention can then be dynamically determined or set by the driver assistance system in each individual case, depending, for example, on the speed of the motor vehicle, the distance between the motor vehicle and the detected obstacle, an estimated or anticipated required stopping time for the motor vehicle depending on the respective situation or environmental conditions, and / or similar factors. The limited duration of the reduced longitudinal guidance intervention can advantageously alert the driver to the situation, while still advantageously reducing the speed of the motor vehicle.However, once the reduced longitudinal guidance intervention has ended, the driver advantageously has the full driving dynamics of the vehicle at their disposal to react to the situation, for example, to avoid the obstacle or to drive past it before it reaches it. The predetermined time period, i.e. the duration of the reduced longitudinal guidance intervention, can advantageously be selected or set, for example, according to a typical driver reaction time. This can then advantageously avoid conflicts between a control intervention performed manually by the driver to steer the vehicle and the automatically performed or controlled reduced longitudinal guidance intervention. The vehicle then advantageously reacts in a manner that the driver is used to or expects, which can also contribute to improved safety.

[0015] Due to the reduced longitudinal guidance intervention, the driver experiences earlier and smaller or weaker braking acceleration, which advantageously has a less severe impact on passenger comfort or driving comfort for the driver or the other vehicle occupants than would be the case with a later but stronger emergency braking intervention. If the detected obstacle is another road user, for example a pedestrian or cyclist or the like, the reduced longitudinal guidance intervention, i.e. the relatively early deceleration of the vehicle, can advantageously signal to the other road user early and thus conveniently that the vehicle or its driver assistance system has detected the obstacle and has already correctly recognized and assessed the situation with regard to a potential collision risk.This can advantageously lead to an overall improvement in traffic flow, since pedestrians or cyclists, for example, who are signaled in this way at an early stage that they have been detected by the motor vehicle or the driver assistance system, will often cross a road used by the motor vehicle at an appropriate early stage, for example, and not only when the motor vehicle has come to a complete standstill.

[0016] The reduced longitudinal guidance intervention contributes to improving road safety in several ways. Firstly, the reduced longitudinal guidance intervention can serve as a warning to the driver, alerting them that the driver assistance system has detected or recognized an obstacle or a risk of collision. Since this occurs earlier than the emergency braking intervention, the driver then has sufficient time, if necessary, to avoid the collision with a less risky and more reliably controllable maneuver than the emergency braking intervention, for example, by bringing the vehicle to a standstill or avoiding the obstacle.The driver is less startled or distracted due to the reduced braking acceleration that occurs with the weakened longitudinal guidance intervention compared to the emergency braking intervention, so that he or she can assess the respective situation more quickly, reliably and safely and react accordingly.

[0017] If the obstacle or the corresponding collision risk was incorrectly or incorrectly detected by the driver assistance system, the reduced longitudinal guidance intervention is advantageously associated with a significantly lower loss of comfort than with an incorrectly performed, i.e., actually unnecessary, emergency braking intervention. This also advantageously enables other vehicles following the vehicle to react more safely to avoid a collision with the vehicle than would be the case if the emergency braking intervention were performed.

[0018] Even if the driver does not take action or react to the reduced longitudinal guidance intervention, for example because he is distracted or relies on the control of the vehicle by the driver assistance system, the reduced longitudinal guidance intervention makes a beneficial contribution to improving safety, since as the vehicle approaches the obstacle, the speed of the vehicle is already reduced by the reduced longitudinal guidance intervention and thus the initial situation for the emergency braking intervention is improved, so that there is a better chance of avoiding the collision and bringing the vehicle to a safe stop.

[0019] The present invention thus represents an improvement over conventional collision avoidance systems by offering a predictive comfort response in the form of a reduced longitudinal guidance intervention, i.e., a predictive comfort intervention when obstacles are detected. The driver assistance system can be configured to automatically switch from the second functionality to the first functionality when the motor vehicle has approached the detected obstacle sufficiently close to the emergency braking intervention to avoid the collision. The relative spatial arrangement and speed between the motor vehicle and the obstacle, as well as the driver's reaction, can be continuously monitored and evaluated by the driver assistance system, and taken into account for controlling or activating the motor vehicle.

[0020] An obstacle within the meaning of the present invention can be a physical obstacle, for example, an object or another road user located on or approaching a trajectory of the motor vehicle. Likewise, in the context of road traffic regulations, the obstacle can be understood as a point or area on the road or as a feature of road equipment at which the motor vehicle must be brought to a standstill. In this sense, for example, a traffic light or a stop sign that is set to "red" can be understood as an obstacle. Since other road users typically rely on the motor vehicle stopping at such points or features, emergency braking intervention, and in particular the reduced longitudinal guidance intervention, can also be justified and useful in the interests of road safety.

[0021] As described in connection with the emergency braking intervention, the weakened longitudinal guidance intervention can also be initiated by the driver assistance system, for example, by the driver assistance system transmitting a corresponding control command, for example via an on-board electrical system of the motor vehicle, to the braking system and / or another device of the motor vehicle, for example an engine control unit, a transmission control unit, a fuel pump and / or the like.

[0022] In the present invention, the driver assistance system is configured according to one aspect to cause the motor vehicle to switch to coasting mode as the reduced longitudinal guidance intervention in order to utilize an engine braking effect to slow the motor vehicle. Coasting mode or overrun mode refers, in the technical sense, to a driving state of the motor vehicle in which, when the traction is not interrupted, a drive motor is towed by the motor vehicle, i.e., is kept in rotation by a movement of the motor vehicle. In other words, with the reduced longitudinal guidance intervention, there is no need to activate or actuate a dedicated braking system of the motor vehicle. By transitioning to coasting mode, the reduced longitudinal guidance intervention can advantageously be designed or implemented in a particularly comfortable and energy-saving manner.For example, many motor vehicles today have an overrun cut-off system that interrupts the fuel supply when the vehicle is coasting. In electric or hybrid vehicles, recuperation can be carried out during coasting to recover electrical energy. Depending on the design of the vehicle, coasting may be accompanied or associated with a characteristic noise. This can be different from the noise generated by the vehicle during normal driving, i.e. the operating noise of the vehicle during rolling or braking with a disconnected power connection, for example with the clutch engaged or disengaged. This can advantageously serve as additional information for the driver, enabling them to be particularly reliably aware of the situation, i.e. the obstacle detected by the driver assistance system.

[0023] According to a further aspect of the present invention, the driver assistance system is configured to monitor acceleration values ​​of the motor vehicle provided by an acceleration sensor and to automatically adjust or control the reduced longitudinal guidance intervention such that, during the reduced longitudinal guidance intervention, a braking acceleration of the motor vehicle of at most 1 m / s 2< , in particular a braking acceleration in the range from 0.3 m / s 2< to 1 m / s 2< , occurs. These acceleration values ​​are to be understood in the direction of travel and in the sense of a deceleration or slowing down of the motor vehicle in the direction of travel. Expressed as acceleration, the stated values ​​can therefore also be given a negative sign. In order to achieve or maintain the specified braking accelerations or braking acceleration values, different measures can be applied and different influences can be taken into account.For example, depending on the current gradient of a section of road traveled by the motor vehicle, switching the motor vehicle to coasting mode may be sufficient to decelerate the vehicle to the specified braking acceleration values. However, if the motor vehicle is moving downhill, for example, the driver assistance system can perform or initiate additional or alternative control of the vehicle's braking system in order to achieve the specified braking acceleration. The acceleration sensor can be part of the driver assistance system. Likewise, the driver assistance system can, for example, have a data interface via which the acceleration values ​​can be transmitted or received.

[0024] By limiting the braking acceleration to the specified values ​​during the reduced longitudinal guidance intervention, this can be advantageously made more comfortable and thus prevent the driver from being startled or distracted. This advantageously makes the driver's attention particularly safe and comfortable to the respective situation, i.e., to the detected obstacle. In contrast, for the emergency braking intervention, a braking acceleration of more than 4 m / s 2< , for example, in the range of 5 m / s 2< to 6 m / s 2< , can be provided in order to bring the vehicle to a standstill safely and as quickly as possible.

[0025] In a further advantageous embodiment of the present invention, the driver assistance system is configured to use a maximum of 25% of the maximum braking power of the motor vehicle for the reduced longitudinal guidance intervention. The maximum braking power corresponds to the technically maximum braking force applied by a braking system of the motor vehicle. This maximum braking power can, in particular, be a braking power intended for emergency braking intervention. For the reduced longitudinal guidance intervention, the braking system can therefore apply or use a maximum of a quarter of the maximum braking force intended according to the specifications. However, the braking power can also be generated by other measures.For example, the braking power or braking effect of the engine during overrun can also be less than 25% of the maximum braking power and can therefore also be consistently used for the reduced longitudinal guidance intervention in this embodiment of the present invention. The braking power actually applied or effective can be automatically determined by the driver assistance system based on corresponding data from the respective operating devices, for example, the vehicle's braking system. Likewise, the driver assistance system can detect and consider acceleration values ​​of the vehicle provided by an acceleration sensor in order to determine the braking power with which the vehicle is currently being decelerated.Depending on the braking power or actual braking deceleration or braking acceleration of the motor vehicle determined by the driving assistance system in this way, the driving assistance system can then automatically adapt a control command issued to initiate the reduced longitudinal guidance intervention in order to ensure that during the reduced longitudinal guidance intervention the actual braking power applied or used reaches a maximum of 25% of the maximum braking power or, correspondingly, an actual braking acceleration of the motor vehicle during the reduced longitudinal guidance intervention corresponds to a maximum of 25% of a maximum specified braking acceleration of the motor vehicle during an emergency braking or full braking.By limiting the braking power or braking acceleration used for the reduced longitudinal guidance intervention in this way, it can be advantageously achieved that the reduced longitudinal guidance intervention is comfortable for the driver and does not have a distracting or frightening effect on the driver. At the same time, the reduced longitudinal guidance intervention can be designed to be sufficiently strong so that it can be reliably recognized by the driver and interpreted or understood as an indication of the detected obstacle and the correspondingly required increased attention.

[0026] In a further advantageous embodiment of the present invention, the driver assistance system is configured to recognize as the obstacle another road user located next to a lane traveled by the motor vehicle, and to detect road features of a currently traveled section of road on the basis of the provided environmental data. The driver assistance system is then further configured to initiate the reduced longitudinal guidance intervention only if both the obstacle has been recognized and a feature of the road features has been identified which indicates a planned stopping position for the motor vehicle, at least depending on the situation. Such a feature of the road features can in particular be a traffic light system, a crossing system, a transverse marking and / or a right-of-way traffic sign.The fact that the feature of the road equipment indicates a stopping position for the motor vehicle means that, at least in certain situations, according to a road traffic regulation or in the interests of road safety, it is provided that the motor vehicle stops at the stopping position, i.e. at or in front of the corresponding feature of the road equipment.

[0027] In this sense, it is intended, for example, that the motor vehicle stops at a corresponding stop position in front of a traffic light if the traffic light for the motor vehicle is "red." Similarly, it is intended, for example, that the motor vehicle stops at a pedestrian crossing (also known as a zebra crossing) if a pedestrian is on the pedestrian crossing or approaching it. In this case, it is therefore intended that the road user is, for example, a pedestrian or cyclist who is located or moving next to the traffic lane on a side space of the respective road, for example, on a sidewalk, pavement, cycle path, or the like.This road user can then at least potentially represent an obstacle or a risk of collision for the motor vehicle, since the road user can move in an unforeseen manner onto the lane, i.e. onto a roadway used by the motor vehicle.

[0028] However, it is not practical to always decelerate or slow down a motor vehicle when a pedestrian or cyclist is located or moving next to the lane, which is particularly obvious in an inner-city area. The present embodiment of the invention is based on the recognition that other road users, such as pedestrians and cyclists, often cross a lane or roadway in an area or vicinity of a designated crossing or at a point where motor vehicles traveling in the respective lane or roadway typically stop or should normally stop. This includes situations or areas in which crossing the lane or roadway, for example by pedestrians, is not intended at that point.But even in areas surrounding a crossing facility, it is often observed in practice that, for example, pedestrians enter the respective lane or roadway adjacent to the area actually intended for crossing, for example because a shorter or more direct route is available for them. Likewise, it regularly occurs in practice that, for example, pedestrians or cyclists cross the roadway at a traffic light even when the traffic light is showing "red" for them, meaning that pedestrians or cyclists are not intended to cross the roadway at that time.

[0029] While it can be considered compliant to bring a motor vehicle to a stop at the respective road feature, either manually or automatically controlled by the driver assistance system, this alone often cannot provide optimal safety for all road users involved. The driver assistance system according to the invention therefore provides for the attenuated longitudinal guidance intervention to be carried out when approaching a corresponding road feature at least if another road user, in particular a pedestrian, cyclist, or user of another small vehicle, sports equipment, or the like, is in the vicinity of the respective feature. This is also intended, in particular, if the motor vehicle would not automatically be required to stop in the respective situation according to the road traffic regulations, for example, because a traffic light for the motor vehicle is green.However, due to the described frequently observed behavior of other road users in the area of ​​corresponding features of the road equipment, the driver assistance system according to the invention can advantageously contribute particularly effectively to improving road safety in corresponding areas or situations, without unduly impairing the comfort of the motor vehicle driver or traffic flow along the respective section of road. Taking into account the described combination of conditions for initiating the reduced longitudinal guidance intervention thus represents an optimal compromise in terms of safety, comfort, and traffic efficiency.

[0030] In a further advantageous embodiment of the present invention, the driver assistance system is configured to recognize, as the obstacle, a feature of road equipment on a currently traveled section of road, which indicates a stopping position for the motor vehicle, at least depending on the situation. Furthermore, the driver assistance system is then configured to use the environmental data to detect whether another road user, in particular a pedestrian, cyclist, or user of a small vehicle or sports equipment, is located in the area of ​​the recognized feature of the road equipment. Such a feature can be, in particular, a traffic light, a crossing facility, a transverse marking, and / or a right-of-way traffic sign. In particular, this feature can be the feature already mentioned elsewhere herein.Furthermore, the driver assistance system is then configured to adapt a temporal profile, i.e., a progression or progression curve of the intensity of a deceleration of the motor vehicle initiated by the driver assistance system as the motor vehicle approaches the detected feature of the road equipment, depending on a respective detection result. The driver assistance system thus adapts the deceleration, which may in particular be or include the attenuated longitudinal guidance intervention, depending on whether or not a corresponding other road user has been detected or recognized in the area, i.e., on the feature or in the vicinity of the feature.

[0031] To this end, the driver assistance system automatically sets a progressive deceleration profile if another road user is detected. If, however, no other road user is detected, the driver assistance system automatically sets a degressive deceleration profile. In other words, the vehicle's approach behavior to the detected feature is set or adapted depending on the situation. For example, the detected feature may be a traffic light that shows "red" for the vehicle. If the vehicle or the driver assistance system detects no other road users in the vicinity of the traffic light, in particular no pedestrians or cyclists, the vehicle can be automatically decelerated according to the progressive profile, i.e., with initially relatively low braking acceleration, which then increases, i.e., becomes stronger, as the vehicle approaches the feature.This allows the traffic space in front of the corresponding road feature to be filled particularly quickly and efficiently, for example, by the vehicle itself and other vehicles following it. However, if another corresponding road user is detected in the vicinity of the traffic light, the vehicle can be automatically decelerated according to the depressive profile, initially increasing the braking acceleration and then decreasing it as the feature approaches. This advantageously provides the other road user with a particularly early and clear signal that the vehicle or driver assistance system has detected them, correctly assessed and classified the respective situation, and is accordingly under control.This can benefit both safety and comfort, especially for other road users, as well as traffic flow in the area of ​​the respective road feature.

[0032] In a further advantageous embodiment of the present invention, the driver assistance system is configured to issue a takeover request to the driver of the motor vehicle to assume control of the motor vehicle when the reduced longitudinal guidance intervention is carried out. In other words, the driver is informed that they should assume manual control of the motor vehicle. In particular, if the driver assistance system does not enable or cannot assume fully automated and autonomous driving of the motor vehicle, an optimal compromise between comfort and safety is achieved in this way. For example, the driver assistance system or another driver assistance system of the motor vehicle can assume longitudinal guidance of the motor vehicle as long as or in areas where no obstacles are detected.If, however, an obstacle is detected, the reduced longitudinal guidance intervention alone improves safety or creates a safer starting point for subsequent reactions or interventions. Furthermore, the takeover request can be used to ensure that the driver takes over manual control or steering of the vehicle in situations where an actual or potential obstacle has been detected, which, at least based on the current state of the art, can mean improved safety in vehicle driving. Irrespective of this, the primary functionality of the driver assistance system can remain operational.

[0033] The takeover request can be issued or configured, for example, as a visual, acoustic and / or haptic indication or as a corresponding signal. The takeover request can therefore be or include, for example, a displayed symbol, a signal or warning tone, a voice output and / or a vibration generated by a corresponding actuator and / or the like. The combination of the weakened longitudinal guidance intervention and the takeover request provided here is particularly advantageous because it creates at least two separate and different effects or events that can alert the driver to the detected obstacle, so that the driver can be particularly reliably alerted to the detected obstacle or the corresponding situation.In addition, the reduced longitudinal guidance intervention provides the driver with sufficient reaction time to assess the respective situation in response to the takeover request and to take over control or steering of the vehicle and then still have enough time to react appropriately to the situation, since the reduced longitudinal guidance intervention can extend the time until a possible collision with the detected obstacle.

[0034] To carry out the described measures or sequences, the driver assistance system according to the invention, regardless of its specific design, can comprise a computer-readable data memory and a processor device connected to it, for example, a microchip, microprocessor, or microcontroller. A computer program or program code encoding or representing the described measures of the sequences can then be stored on the computer-readable data memory as a storage medium. When this computer program or program code is executed by the processor device, the processor device or the driver assistance system is then prompted to initiate or execute the described measures or sequences.

[0035] A further aspect of the present invention is a motor vehicle having an environmental sensor system for acquiring environmental data that characterizes the current environment of the motor vehicle. The motor vehicle according to the invention also has a driver assistance system according to the invention coupled to the environmental sensor system. The motor vehicle according to the invention can therefore, in particular, be the motor vehicle mentioned in connection with the driver assistance system according to the invention. Accordingly, the motor vehicle according to the invention can have the properties and / or parts or components mentioned in connection with the driver assistance system according to the invention.

[0036] A further aspect of the present invention is a method for operating a driver assistance system for a motor vehicle and / or for operating a motor vehicle with a driver assistance system. The driver assistance system serves to assist a driver of the motor vehicle during longitudinal guidance of the motor vehicle. The method according to the invention provides that environmental data characterizing a current environment of the motor vehicle is recorded and provided or transmitted to the driver assistance system. In a further method step of the method according to the invention, this environmental data is processed by the driver assistance system to detect an obstacle located in front of the motor vehicle in the direction of travel.In the method according to the invention, it is then further provided that the driver assistance system initiates a longitudinal guidance intervention to slow down the motor vehicle, which is weaker than an emergency braking intervention, as soon as the obstacle has been detected and before the motor vehicle has approached the obstacle so close that a collision with the obstacle can only be prevented by the emergency braking intervention. In other words, the method according to the invention serves to operate a driver assistance system according to the invention and / or to operate a motor vehicle according to the invention. The method according to the invention can therefore comprise the measures, sequences or processes described in connection with the driver assistance system according to the invention. This includes, in particular, those sequences or processes which are not explicitly described here in connection with the method according to the invention or explicitly as part of the method according to the invention.The computer program or program code stored on the computer-readable data storage device mentioned in connection with the driver assistance system according to the invention can, in particular, encode or represent the method according to the invention or the method steps of the method according to the invention. Executing this computer program or program code can, in particular, cause or initiate automatic execution of the method according to the invention.

[0037] The invention also includes further developments of the motor vehicle according to the invention and of the method according to the invention that have features as described in connection with the further developments of the driver assistance system according to the invention, and vice versa. To avoid unnecessary redundancy, the corresponding further developments are not described separately here for all these aspects of the present invention.

[0038] An exemplary embodiment of the invention is described below. It shows: Fig. 1 shows a schematic plan view of a traffic scene in which a motor vehicle equipped with a driver assistance system is traveling on a road; Fig. 2 shows an exemplary schematic flowchart of a method for operating a driver assistance system of a motor vehicle.

[0039] The exemplary embodiment explained below is a preferred embodiment of the invention. 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 to be considered as 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.

[0040] Fig. 1 shows a schematic plan view of a traffic scene with a section of a road 1. A motor vehicle 3, controlled by a driver 4, is moving along a lane 2 of the road 1. The motor vehicle 3 has an environmental sensor system 5 that records environmental data that characterizes the environment of the motor vehicle 3, in this case the traffic scene shown. Furthermore, the motor vehicle 3 has a driver assistance system 6 that supports the driver 4 in longitudinal guidance of the motor vehicle 3 based on environmental data provided by the environmental sensor system 5.

[0041] In the traffic scene depicted here, the motor vehicle 3 is at a current position 7 and is moving forward in the direction of travel towards a traffic island 8. In the area of ​​the traffic island 8, there is a pedestrian 9. Schematically indicated here is an emergency braking position 10, at which the motor vehicle 3 must begin an emergency braking intervention with maximum deceleration or braking power at the latest in order to come to a standstill at a designated safe stopping position 11, also schematically indicated here, in order to avoid a collision with the pedestrian 9.

[0042] Fig. 2 shows an exemplary schematic flow chart 12 of a method for operating the driver assistance system 6 or the motor vehicle 3. The method steps of the method are described below with reference to Fig. 1 explained. The method steps and their linkage can be understood as blocks, program functions, or program modules of a corresponding computer program that implements the method. However, an actual implementation may differ from the diagram or flow chart 12 presented here merely as an example for explanation purposes.

[0043] The process starts in a process step or program step S1. Here, for example, motor vehicle 3 can be started or driver assistance system 6 can be put into operation.

[0044] In a program step S2, the environmental data are recorded by the environmental sensor system 5 and transmitted to the driver assistance system 6. In this case, the environmental sensor system includes a camera, which Fig. 1records and displays the traffic scene shown, so that the environmental data depict at least lane 2 in the direction of travel in front of the motor vehicle 3, the traffic island 8 and the pedestrian 9.

[0045] In a program step S3, the environmental data are processed by the driver assistance system 6, and it is detected or determined whether there is an obstacle in front of the motor vehicle 3 in the direction of travel. If this is not the case, for example, because the distance of the motor vehicle 3 to the traffic island 8 and the pedestrian 9 is still greater than the range of the environmental sensors 5, the method follows a loop-shaped path 13. The environmental data is thus continuously recorded and processed.

[0046] If, however, an obstacle is detected in program step S3, the method follows a program path 14 to a program step S4.

[0047] In program step S4, the obstacle is classified or identified. In this case, the obstacle is identified as pedestrian 9, after which the method follows a program path 15 to a program step S5.

[0048] In program step S5, the driver assistance system determines whether the detected pedestrian 9 is located on a roadway, i.e., in lane 2 used by the motor vehicle 3. If this is the case, the method follows a program path 16 to a program step S6.

[0049] In program step S6, the driver assistance system determines whether the motor vehicle 3 at the current position 7 has already approached the detected obstacle sufficiently close to the point where an emergency braking intervention with maximum deceleration is necessary to avoid or mitigate a collision with the detected obstacle. In other words, it determines whether the motor vehicle is already at the emergency braking position 10 or has even already exceeded it. If this is the case, the method follows a program path 17 to a program step S7, in which the driver assistance system 6 initiates the emergency braking intervention.If, however, the motor vehicle 3 is still farther away from the detected obstacle at the current position 7, so that the emergency braking intervention is not yet necessary, the method proceeds from program step S6 along a program path 18 to a program step S8, in which a longitudinal guidance intervention that is weaker than the emergency braking intervention is initiated by the driver assistance system 6. At the same time, in method step S8, a takeover request can be issued to the driver 4 to request the driver to assume manual control or steering of the motor vehicle 3.

[0050] If, however, it was determined in program step S5 that the detected obstacle, in this case pedestrian 9, is located next to lane 2, for example on a sidewalk, the method follows a program path 19 to a program step S9.

[0051] In program step S9, the driver assistance system 6 determines whether, based on the environmental data, a feature of road equipment can be detected which, at least depending on the situation, provides for or indicates a stopping of the motor vehicle 3. In the present case, the traffic island 8 is detected as such a feature, in front of which a stopping of the motor vehicle 3 is provided at the stopping position 7, provided that the pedestrian 9 intends to cross lane 2 or road 1 in the area of ​​the traffic island 8. Since the traffic island 8 has been detected in this case, the method follows a program path 20 to a program step S10, in which the driver assistance system 6 sets a degressive profile for a deceleration or slowing down. Subsequently, in this case, program step S8, i.e. the weakened longitudinal guidance intervention, is also executed, in this case with the set degressive deceleration profile.

[0052] However, if in a different situation or traffic scene the pedestrian 9 is located next to the lane 2 and no corresponding feature of the road equipment is detected, for example the traffic island 8 is not present, the method follows a loop-shaped program path 21 starting from the program step S9 in order to run through the method again as long as the motor vehicle 3 or the driver assistance system 6 is in operation.

[0053] If in program step S4 the obstacle was identified as a feature of the road equipment which requires the motor vehicle to stop at least depending on the situation, the method follows a program path 22 to a program step S11.

[0054] In this case, traffic island 8 was identified as the obstacle. In program step S11, the driver assistance system 6 then checks whether another road user, in particular a pedestrian 9 or cyclist, is located in the area of ​​the detected obstacle and is crossing or potentially attempting to cross road 1 in the area of ​​the detected feature, in this case, at traffic island 8.

[0055] If this is not the case, i.e., if no other road user is nearby, the method follows a program path 23 to a program step S12, in which the driver assistance system 6 sets a progressive profile for deceleration or slowing down. However, since driving through an area or section of road with a corresponding road feature can always represent a potentially dangerous situation, program step S8, i.e., the weakened longitudinal guidance intervention, is also executed in this case, in this case with the progressive deceleration profile. This can be the case, in particular, if the detected road feature requires the motor vehicle 3 to actually stop in the respective situation, for example, if the feature is a traffic light that is set to "red."If stopping of the motor vehicle 3 is not intended in the respective situation, the execution of the weakened longitudinal guidance intervention can alternatively be omitted following a program path 24.

[0056] If, however, it is determined in program step S11 that another road user is in the vicinity or surrounding the detected obstacle, the method proceeds from program step S11 to a program step S13. In program step S13, as in program step S10, a progressive profile for the deceleration or slowing down of motor vehicle 3 is set by driver assistance system 6. The method then continues as described with program step S5.

[0057] According to the described method, the driver assistance system 6 thus offers a predictive comfort intervention, for example, in the case of a crossing pedestrian 9. If such a crossing pedestrian 9 is detected by the vehicle or environmental sensors 5 and the driver assistance system 6, the driver assistance system 6 reacts with such a predictive comfort intervention, i.e., with the weakened longitudinal guidance intervention. For this purpose, for example, the motor vehicle 3 can transition to coasting mode, i.e., be initiated by the driver assistance system 6. A resulting speed reaction can, if necessary, contribute to de-escalating the respective situation, control driver attention, and give the driver 4 an impression of the driver assistance system 6's understanding of the situation.

[0058] Specifically, it is provided here that, according to at least one embodiment of the described method or of the driver assistance system 6, the approach behavior of the motor vehicle 3 to a specific feature of road equipment, for example a pedestrian crossing with a traffic light system, is varied. The driver assistance system 6 is configured, for example, to brake or stop the motor vehicle 3 with a progressive deceleration at a red traffic light, which signals the motor vehicle 3 to stop, if no pedestrian 9 has been detected in the vicinity of the traffic light. If, however, the pedestrian 9 is detected, a deceleration of the motor vehicle 3 can be initiated early on according to the degressive profile in order to signal to both the driver 4 and the detected pedestrian 9 that the respective situation has been correctly detected and is under control by the driver assistance system 6 or the motor vehicle 3.

[0059] Overall, the examples described show how road safety can be increased in a particularly convenient way.

Claims

1. Driver assistance system (6) for a motor vehicle (3) for assisting a driver (4) of the motor vehicle (3) during longitudinal guidance of the motor vehicle (3), wherein the driver assistance system (6) is designed - to detect an obstacle (8, 9) located in front of the motor vehicle (3) in the direction of travel, based on environmental data provided by an environmental sensor system (5), and - according to a first functionality, to initiate an emergency braking intervention in order to bring the motor vehicle (3) to a standstill in order to avoid an otherwise imminent collision with the detected obstacle (8, 9), wherein the driver assistance system (6) is also designed to initiate, according to a second functionality, a longitudinal guidance intervention, which is attenuated compared to the emergency braking intervention, to slow down the motor vehicle (3) as soon as the obstacle (8, 9) is detected and before the motor vehicle (3) has come so close to the obstacle (8, 9) that the collision can only be prevented by the emergency braking intervention, characterized in that the driver assistance system (6) is designed to effect the attenuated longitudinal guidance intervention only for a predetermined period of time after the obstacle (8, 9) has been detected and to terminate it before the motor vehicle (3) has come so close to the obstacle (8, 9) that the collision can only be prevented by the emergency braking intervention, so that, after the attenuated longitudinal guidance intervention has been terminated, the full driving dynamics of the motor vehicle (3) are available to the driver, and to automatically switch from the second functionality to the first functionality when the motor vehicle (3) has come so close to the detected obstacle (8, 9) that the emergency braking intervention is necessary to avoid the collision, wherein the driver assistance system (6) is designed to cause the motor vehicle (3) to switch to overrun mode as the attenuated longitudinal guidance intervention, in order to utilize an engine braking effect to slow down the motor vehicle (3), and / or the driver assistance system (6) is designed to monitor acceleration values of the motor vehicle (3) provided by an acceleration sensor and to automatically control the attenuated longitudinal guidance intervention such that a braking acceleration of the motor vehicle (3) of at most 1 m / s2 is produced.

2. Driver assistance system (6) according to claim 1, characterized in that the driver assistance system (6) is designed to use at most 25% of a maximum braking power of the motor vehicle (3) for the attenuated longitudinal guidance intervention.

3. Driver assistance system (6) according to either of the preceding claims, characterized in that the driver assistance system (6) is designed to monitor acceleration values of the motor vehicle (3) provided by an acceleration sensor and to automatically control the attenuated longitudinal guidance intervention such that a braking acceleration in the range of 0.3 m / s2 to 1 m / s2 is produced.

4. Driver assistance system (6) according to any of the preceding claims, characterized in that the driver assistance system (6) is designed to detect, as the obstacle (8, 9), another road user (9) located next to a lane (2) traveled on by the motor vehicle (3), and to detect street furniture of a portion of road (1) currently being traveled on on the basis of the environmental data provided, and to initiate the attenuated longitudinal guidance intervention only if both the obstacle (9) has been detected and an additional feature (8) of the street furniture has been identified that indicates a planned stopping position (11) for the motor vehicle (3), in particular a traffic light system, a crossing installation (8), a crossing marking and / or a right-of-way traffic sign.

5. Driver assistance system (6) according to any of the preceding claims, characterized in that the driver assistance system (6) is designed to detect, as the obstacle (8, 9), a feature (8) of street furniture of a portion of road (1) currently being traveled on that indicates a planned stopping position (11) for the motor vehicle (3), and to detect, on the basis of the environmental data, whether another road user (9) is in the region of the detected feature (8) of the street furniture, and to adjust a time profile of a deceleration of the motor vehicle (3) caused by the driver assistance system (6) when approaching the feature (8) of the street furniture depending on a corresponding detection result, and to set a progressive profile of the deceleration if no other road users (9) are detected and to set a degressive profile of the deceleration if other road users (9) are detected.

6. Driver assistance system (6) according to any of the preceding claims, characterized in that the driver assistance system (6) is designed to issue a takeover request to the driver to take over control of the motor vehicle (3) when the attenuated longitudinal guidance intervention is carried out.

7. Motor vehicle (3) comprising an environmental sensor system for capturing environmental data that characterize a current environment of the motor vehicle (3), and a driver assistance system (6) according to any of the preceding claims, which is coupled to the environment sensor system.

8. Method for operating a driver assistance system (6) for a motor vehicle (3) and / or for operating a motor vehicle (3) with a driver assistance system (6), comprising the method steps of: - capturing environmental data that characterize a current environment of the motor vehicle (3), and providing the environmental data to the driver assistance system (6), and - processing the environmental data by means of the driver assistance system (6) to detect an obstacle (8, 9) located in front of the motor vehicle (3) in the direction of travel, - initiating a longitudinal guidance intervention which is attenuated compared to an emergency braking intervention in order to slow down the motor vehicle (3) by means of the driver assistance system (6) as soon as the obstacle (8, 9) has been detected and before the motor vehicle (3) has come so close to the obstacle (8, 9) that a collision of the motor vehicle (3) with the obstacle (8, 9) can only be prevented by the emergency braking intervention, characterized by - activating the attenuated longitudinal guidance intervention only for a predetermined period of time after the obstacle (8, 9) has been detected by the driver assistance system (6), - terminating the attenuated longitudinal guidance intervention before the motor vehicle (3) has come so close to the obstacle (8, 9) that the collision can only be prevented by the emergency braking intervention, so that after the attenuated longitudinal guidance intervention has been terminated, the full driving dynamics of the motor vehicle (3) are available to the driver, and - automatically switching the driver assistance system (6) from the second functionality to the first functionality when the motor vehicle (3) has come so close to the detected obstacle (8, 9) that emergency braking intervention is necessary to avoid the collision, wherein the driver assistance system (6) causes the motor vehicle (3) to switch to overrun mode as the attenuated longitudinal guidance intervention, in order to utilize an engine braking effect to slow down the motor vehicle (3), and / or the driver assistance system (6) monitors acceleration values of the motor vehicle (3) provided by an acceleration sensor and automatically controls the attenuated longitudinal guidance intervention such that a braking acceleration of the motor vehicle (3) of at most 1 m / s2 is produced.