WO2018158007A1 - Method for operating a driver assistance system of a motor vehicle and motor vehicle - Google Patents

Abstract

The invention relates to a method for operating a driver assistance system (4) of a motor vehicle (1), which takes into account a desired distance of the vehicle (1) to a preceding vehicle (2) for carrying out a function of the driver assistance system (4). The desired distance is determined by the driver assistance system (4) in accordance with at least one quality criteria which evaluates a detectability of a traffic situation in an area in the front of the vehicle (1).

Description

 Method for operating a driver assistance system of a motor vehicle and motor vehicle

The invention relates to a method for operating a driver assistance system of a motor vehicle, which takes into account a desired distance of the motor vehicle to a preceding foreign vehicle for performing a function of the driver assistance system. In addition, the invention relates to a motor vehicle. Driver assistance systems of motor vehicles, which take into account a desired distance to a preceding foreign vehicle, have been known for some time, for example as adaptive cruise control (ACC). The desired distance may be conventionally predetermined by the driver of the motor vehicle or be determined as a function of other variables, for example the speed of the motor vehicle. In the case of an adaptive cruise control system, a relatively short setpoint distance results in a more intensive driving engagement for a detected shortening of an actual distance, for example after a sudden braking of the other vehicle, than in a longer setpoint distance.

In an exclusively driver-side specification of the desired distance or an exclusive consideration of the speed of the motor vehicle, however, no consideration can be given to various influences that may cause a shortening of the actual distance detected on the vehicle side. The driver assistance system must therefore respond to unforeseen changes in the actual distance, which lead in the case of the distance control cruise control to a large number of driving interventions. An occupant, in particular the driver of the motor vehicle, feels such driving interventions, such as a sudden braking or acceleration, typically as uncomfortable, so that the user friendliness of the driver assistance system suffers. The invention is therefore based on the object of specifying a possibility for more user-friendly operation of a driver assistance system that takes into account a setpoint distance to a preceding third-party vehicle.

To achieve this object, a method of the type mentioned is provided according to the invention, that the target distance is determined by the driver assistance system as a function of at least one Gütemaßes, which assesses a detectability of a traffic situation in a vehicle apron of the motor vehicle.

The invention is based on the idea of making the target distance to the other vehicle dependent on the detectability, in other words on the reliability or security of the detection of the vehicle apron. It has been recognized that, given a sufficiently large setpoint distance selected according to the invention, it is also possible to react to unforeseeable events by the driver assistance system in such a way that an occupant of the motor vehicle perceives the reaction as considerably more comfortable, because, for example, jerky braking or acceleration interventions are avoided. Namely, if a low reliability of detection of the vehicle apron and thus a poor detectability descriptive quality measure is given, there is a higher probability of an unexpected change in the current state. In accordance with the invention, this is taken into account by adapting the desired distance to this increased probability. Compared to conventional driver assistance systems, for example, take into account only a driver-specified or determined only from the speed of the motor vehicle target distance, the invention allows a much more user-friendly operation of the driver assistance system or of the motor vehicle as a whole.

Typically, the driver assistance system uses the desired distance as a reference variable of a control realized by the driver assistance system. The driver assistance system preferably comprises a control device, which che takes into account the nominal distance and / or determines the quality measure. The traffic situation can be described, for example, by a driving state of one or more road users driving ahead of the motor vehicle, in particular including the foreign vehicle. The driving state can be described, for example, by a speed and / or an acceleration or braking behavior of the road users and / or distances of the road users to one another and / or the presence of a traffic jam. As a traffic situation, the condition of a road surface and / or the risk of wild animal movements can also be detected. The detected traffic situation can be decisive for the specification of the desired distance, wherein an adaptation, for example by providing a safety margin, takes place as a function of the at least one quality measure. The function of the driver assistance system preferably implements an adaptive cruise control (ACC). This can perform longitudinal intervention in dependence on the nominal distance and a detected actual distance.

According to a first advantageous embodiment of the method according to the invention, a quality measure is used which evaluates the detectability of the traffic situation by means of at least one input data of the driver assistance system for determining the setpoint distance providing vehicle system of the motor vehicle. Such a quality measure thus represents the detectability of the traffic situation by the vehicle-side vehicle system, so ultimately the quality and / or reliability of the input data. In other words, the quality measure describes how safe the traffic situation or the vehicle apron is described by the input data. It can thus be advantageously estimated whether sufficient information is available to detect possible effects of a change in the traffic situation on one's own driving behavior.

The input data are preferably those of a sensor device which detects the surroundings of the motor vehicle. This can, for example, at least one camera and / or at least one radar sensor and / or at least comprise a lidar sensor. Alternatively or additionally, a vehicle system may be a communication device communicating with a transmission device external of the motor vehicle. The traffic situation can therefore also be detected by communication data received by the communication device. Typically, the communication device is operated using a Car2x protocol.

The detectability of the traffic situation is preferably evaluated by means of the vehicle system of the motor vehicle as a function of availability of the vehicle system. A change in the availability is for example in case of failure or impairment of the function of a sensor of the sensor device and / or the communication device. It is conceivable, for example, that when the signal strength of a received signal of the communication device is low, a quality measure describing a poorer detectability is determined. Alternatively or additionally, the detectability of the traffic situation can be evaluated as a function of a quality of sensor data of the sensor device and / or a degree of contamination of a sensor of the sensor device. A further advantageous embodiment of the method according to the invention provides that a quality measure is used which assesses the detectability of the traffic situation by a driver of the other vehicle and / or by means of at least one vehicle system of the other vehicle, in particular a sensor device that detects its surroundings. In this design, it is therefore not based on the detectability of the traffic situation from the perspective of the motor vehicle, but from the perspective of the other vehicle. It has namely been recognized that, given a good detectability of the traffic situation by the driver and / or the vehicle system of the other vehicle, fewer unforeseeable reactions to a change in the vehicle apron of the motor vehicle, in particular in a vehicle apron of the other vehicle, can be expected. Unpredictable and / or short-term reactions of the other vehicle to a change The traffic situation can thus be anticipated, which allows a particularly forward-looking operation of the driver-assistance system on the vehicle side. With regard to the detectability of the traffic situation by the driver of the other vehicle, it is preferred if the detectability of the traffic situation by the driver depending on a degree of attention of the driver and / or a degree of fatigue of the driver and / or a degree of contamination of a mirror and / or a disc through which the driver detects the vehicle apron, is assessed. Accordingly, there is a slight driver's attention or greater fatigue, such as can be detected by external vehicle-side, the driver and / or the posture of the driver evaluating the driver's behavior and / or facial expression, or a poor visual quality by means of a mirror and / or by a disc for the driver, which can also be detected by corresponding sensors of the other vehicle, so a lower detectability describing quality measure is determined.

With regard to the detectability of the traffic situation by means of the at least one vehicle system of the foreign vehicle, it may be advantageously provided that the detectability of the traffic situation by means of the vehicle system of the other vehicle depending on availability of the vehicle system and / or a quality of sensor data of the sensor device and / or a degree of contamination a sensor of the sensor device is evaluated. If the other vehicle itself is operated by means of a driver assistance system, for example a distance control system, then the traffic situation may become worse detectable for the aforementioned reasons, which in turn may lead to unpredictable and / or short-term reactions of the vehicle-side driver assistance system.

The motor vehicle expediently receives data for assessing the detectability of the traffic situation by means of the or a communication input. direction of the motor vehicle from the other vehicle. Preferably, the communication device is operated by means of a Car2Car protocol. It is possible that directly and / or indirectly, for example with the interposition of a server, data transmitted from the foreign vehicle to the motor vehicle is received.

In the method according to the invention, it is also advantageous if the detectability of the traffic situation is assessed as a function of weather-related visual restrictions and / or at least partial occlusion of the vehicle apron by the foreign vehicle and / or by another foreign vehicle driving ahead of the foreign vehicle. Weather-related visual restrictions can be, for example, fog and / or precipitation. The detectability of the traffic situation is preferably detected in this case by means of the or a vehicle-side sensor device. In the case of the weather-related visual impairment or the occlusion of the vehicle apron, a quality information describing a poorer detectability can be determined.

It is also preferred in the method according to the invention if the detectability of the traffic situation is taken into account in at least one section of the vehicle apron which lies in front of the other vehicle in the direction of travel. In particular, only the detectability in the at least one section is considered. Finally, it is particularly expedient if, in the presence of a quality measure describing a better comprehensibility, a smaller desired distance is specified than in the case of a quality measure describing a poorer detectability. The object underlying the invention is further achieved by a motor vehicle, comprising a driver assistance system, which is operable according to the inventive method. All statements on the method according to the invention can be analogously to the inventive Motor vehicle transmitted, so that even with this the aforementioned advantages can be achieved.

Further advantages and details of the invention emerge from the exemplary embodiment described below as well as from the drawing. This is a schematic representation and shows a schematic diagram of a motor vehicle according to the invention in a traffic situation with a preceding foreign vehicle and another foreign vehicle. The figure shows an embodiment of a motor vehicle 1 in a traffic situation with an immediately preceding third party vehicle 2 and another foreign vehicle 3, which immediately precedes the foreign vehicle 2. The motor vehicle 1 has a driver assistance system 4, which realizes the function of a distance control cruise control and takes into account for carrying out this function a desired distance of the motor vehicle 1 to the other vehicle 2. The driver assistance system 4 controls demensprechend by braking and accelerating longitudinal guidance interventions an actual distance to the other vehicle 2 to the desired distance. This function is implemented in a control device, for example a control device, of the driver assistance system 4. Furthermore, a sensor device 5 is provided on the motor vehicle side which comprises a plurality of sensors, for example at least one camera and / or at least one radar sensor and / or at least one lidar sensor, detects the vehicle ahead of the motor vehicle 1 and provides the driver assistance system 4 with sensor data. The sensor data thus describe the traffic situation in the vehicle apron, including a section of the vehicle apron in the direction of travel in front of the foreign vehicle 2. The actual distance to the other vehicle 2 is also determined by means of the sensor device 5.

The motor vehicle also has a communication device 6 which can be operated according to a Car2x protocol and provides the driver assistance system 4 with communication data. The communication device 6 receives communication data, which is provided by a stationary, external to the motor vehicle transmitter 7 and also describe the traffic situation. In addition, the communication device 6 receives communication data from a communication device 8 of the foreign vehicle 2.

In the context of a method for operating the driver assistance system 4, the desired distance is determined as a function of a plurality of quality measures which evaluate the detectability of the traffic situation in the vehicle apron of the motor vehicle 1. Initially, a distance to the other vehicle 2 to be observed by the driver assistance system 4 in a conventionally known manner initially flows decisively into the nominal distance. This is determined by the driver assistance system from the detected traffic situation. The traffic situation is described by a driving state of the foreign vehicles 2, 3. The driving state includes a speed, an acceleration or braking behavior of the foreign vehicles 2, 3, their distances from one another and the presence of a traffic jam in the vehicle apron. As a traffic situation, the condition of a road surface and / or the risk of wild animal movements can also be detected. The target distance then results from this determined by the driver assistance system 4 distance and a determined depending on the quality measures surcharge or discount, wherein in the presence of a lower detectability descriptive quality measure a larger target distance is determined than in the presence of a descriptiveness better describing Quality measure and vice versa.

A first quality measure evaluates the detectability of the traffic situation by means of at least one input data of the driver assistance system 4 for determining the target distance providing vehicle system of the motor vehicle 1, wherein the vehicle system presently the sensor device 5 and the communication device 6 are used. The evaluation takes place as a function of availability of the vehicle system, a quality of sensor data of the sensor device 5 and a degree of contamination of a sensor of the sensor device 5. If, for example, a sensor of the sensor device 5 or the entire sensor device 5 fails, the detectability of the Vehicle apron significantly affected, so that the first quality measure describes a poor detectability. The same applies to a failure of the communication device 6, a demolition of a communication connection to the transmitting device 7 or the communication device 8 of the foreign vehicle 2 or a poor signal quality of the received signals of the communication device 6. A poor detectability described by the first quality measure can also result from it in that the sensor device 5 supplies diagnostic data to the driver assistance system 4 which describe a defective quality of the sensor data or a contamination of one of the sensors.

The aforementioned influences mean that the vehicle apron can not be detected reliably enough. The driver assistance system 4 therefore increases the setpoint distance in order to better anticipate unpredictable and / or short-term changes in the driving behavior of the other vehicle 2 and to be able to avoid correspondingly intensive, uncomfortable driving interventions by the driver assistance system 4. A second quality measure assesses the detectability of the traffic situation by a driver 9 of the other vehicle 2 and by vehicle systems of the other vehicle 2. As vehicle systems, the other vehicle present - as the motor vehicle 1 - a sensor device 10 and the communication device 8. These can likewise be connected to a distance control system 11 for carrying out longitudinal guidance operations of the foreign vehicle 2. In contrast to the first quality measure, the second quality measure thus describes how reliably the driver 9 or the communication device 8 and the sensor device 10 can detect the traffic situation. If this detectability is bad, then it can be expected that unpredictable and / or short-term reactions to the traffic situation can take place by the driver 9 or the adaptive cruise control system 1 1 from the perspective of the motor vehicle 1. In this case, too, the target distance is increased in the case of a second quality measure describing a poor detectability. In detail, the detectability of the traffic situation by the driver 9 is evaluated depending on an attention level of the driver 9 and his degree of fatigue. For this purpose, known from the prior art, in particular in the interior of the other vehicle 2 arranged sensors are used, which detect, for example, the facial expressions or posture of the driver 9 and provide appropriate data. In addition, the detectability of the traffic situation by the driver 9 is evaluated depending on a degree of soiling of a mirror and a disk by which the driver detects the vehicle apron. Also, corresponding sensors may be provided on the other vehicle 2, which detect the reflectivity of the mirror or the transparency of the disc.

The detectability of the traffic situation by means of the vehicle systems of the foreign vehicle 2 is evaluated as a function of availability of the vehicle system, a quality of sensor data of the vehicle-side sensor device and a degree of contamination of a sensor of the vehicle-side sensor device. In this respect, reference may be made to the comments on the assessment of the detectability of the traffic situation by means of the vehicle systems of the motor vehicle 1.

All data describing the detectability of the traffic situation by the driver 9 and by means of the vehicle systems of the foreign vehicle 2 are transmitted to the communication device 6 of the motor vehicle 1 via the communication device 8 using a Car2Car protocol. This transmission can take place via a direct wireless connection between the communication devices 6, 8 or indirectly with the interposition of a server, which communicates directly with the communication devices 6, 8 wirelessly.

Finally, a third quality measure assesses the detectability of the traffic situation as a function of weather-related visual restrictions, at least partial obscuring of the vehicle apron by the other vehicle 2 and the other foreign vehicle 3. Weather-related visual restrictions are, for example, fog or precipitation. The detectability of the traffic situation can be evaluated by the driver assistance system 4 on the basis of the sensor data of the sensor device 5, for which purpose image data of the camera or communication data received by the transmitting device 7 can be evaluated with regard to the visual restriction or the coverage.

The quality measures are taken into account together in determining the nominal distance. In a particularly preferred embodiment, only the detectability of the traffic situation in the section of the vehicle apron is considered, which lies in the direction of travel in front of the foreign vehicle 2. As a result, the effort for determining the desired distance can be limited to the section of the vehicle apron that is particularly relevant for anticipating the behavior of the other vehicle 2.

Claims

P A T E N T A N S P R E C H E Method for operating a driver assistance system (4) of a motor vehicle (1), which takes into account a desired distance of the motor vehicle (1) to a preceding foreign vehicle (2) for performing a function of the driver assistance system (4), characterized, the setpoint distance is determined by the driver assistance system (4) as a function of at least one quality measure, which evaluates a detectability of a traffic situation in a vehicle apron of the motor vehicle (1). Method according to claim 1, characterized, a quality measure is used which determines the detectability of the traffic situation by means of at least one input data of the driver assistance system (4) for determining the target distance providing vehicle system of the motor vehicle (1), in particular a sensor device (5) detecting the environment of the motor vehicle (1) and / or a communication device (6) communicating with a transmission device (7) external to the motor vehicle. Method according to claim 2, characterized, the detectability of the traffic situation is assessed by means of the vehicle system of the motor vehicle (1) as a function of availability of the vehicle system and / or a quality of sensor data of the sensor device (5) and / or a degree of contamination of a sensor of the sensor device (5). Method according to one of the preceding claims, characterized, a quality measure is used which evaluates the detectability of the traffic situation by a driver (9) of the foreign vehicle (2) and / or by means of at least one vehicle system of the foreign vehicle (2), in particular of a sensor device (10) which detects its environment. Method according to claim 4, characterized, the detectability of the traffic situation by the driver (9) as a function of a degree of attention of the driver (9) and / or a degree of fatigue of the driver (9) and / or a degree of soiling of a mirror and / or a disc by which the driver (9) the vehicle apron is recorded, evaluated. Method according to claim 4 or 5, characterized, the detectability of the traffic situation is assessed by means of the vehicle system of the preceding foreign vehicle (2) as a function of availability of the vehicle system and / or a quality of sensor data of the sensor device (10) and / or a degree of contamination of a sensor of the sensor device (10). Method according to one of claims 4 to 6, characterized, in that the motor vehicle (1) receives data for assessing the detectability of the traffic situation by means of the or a communication device (6) of the motor vehicle (2) from the other vehicle. Method according to one of the preceding claims, characterized, that the comprehensibility of the traffic situation depends on weather-related visual restrictions and / or at least partial Covering of the vehicle apron by the foreign vehicle (2) and / or by another, the foreign vehicle (2) driving ahead foreign vehicle (3) is assessed. Method according to one of the preceding claims, characterized, that only the detectability of the traffic situation in at least a portion of the vehicle apron is taken into account, which lies in the direction of travel in front of the foreign vehicle (2). Method according to one of the preceding claims, characterized, that in the presence of a quality measure describing a better comprehensibility, a lesser desired distance is specified than in the case of a quality measure describing a poorer comprehensibility. Method according to one of the preceding claims, characterized, the function of the driver assistance system (4) implements a distance control system. Motor vehicle (1), comprising a driver assistance system (4), which is operable in accordance with a method according to one of the preceding claims.