DE102012203228B4 - Method for avoiding or mitigating the consequences of a motor vehicle colliding with an obstacle in a lateral area close to the motor vehicle and driver assistance system - Google Patents

Abstract

Method for avoiding collisions of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle (1) or for reducing the consequences of a collision of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle ( 1) with the following steps: - detecting (S0) an obstacle (2) in the lateral vicinity of the motor vehicle (1), - determining (S2) a driving path (10) of the motor vehicle (1), - determining (S4) a risk of collision Hand of the driving tube (10) of the motor vehicle (1) and the position of the obstacle (2) or the position and the movement of the obstacle (2) and setting (S7) a steering angle (β) of rear wheels (14) of the motor vehicle (1 ) when the risk of collision is determined, in order to avoid the obstacle (2), characterized in that the steering angle (β) of the rear wheels (14) of the motor vehicle (1) is adjusted in such a way that a time up to the collision is a maximum if a collision with the obstacle (2) is unavoidable.

Description

State of the art

The invention relates to a method according to the preamble of claim 1 and a computer program for carrying out such a method. Furthermore, the invention relates to a driver assistance system for avoiding collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle or for reducing the consequences of collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle.

From the DE 10 2008 061 359 A1 a monitoring device for the surroundings of a motor vehicle is known, with which a fixed obstacle arranged on the side of the roadway is detected, the position of the detected obstacle being continuously determined and an imminent collision between the motor vehicle and the obstacle being detected by an evaluation device. If an impending collision of the motor vehicle with the obstacle has been detected, a warning signal is transmitted to the driver of the motor vehicle and, if necessary, a braking intervention or a steering intervention is carried out.

EP 1 447 271 A2 shows a device for monitoring the immediate area of a motor vehicle to avoid collisions with obstacles, with a computer unit calculating a driving path of the motor vehicle as a function of a detected steering angle and other body-related information. To avert an impending collision, an actuator is provided for automatically changing a steering angle or for automatically braking the motor vehicle.

From the generic DE 10 2008 012 685 A1 discloses a motor vehicle with front wheels that can be steered via a steering wheel and rear wheels that can be steered independently of the front wheels via an adjusting device. It is a device for detecting at least the lateral vehicle environment and for determining a possible collision with an obstacle detected in the vehicle environment during a parking or maneuvering operation, taking into account the trajectory that can be determined using the given setting angle of the front and rear wheels. The actuating device can only be actuated to adjust the rear wheels when a possible collision is detected in such a way that a collision is avoided. Also from the EP 1 908 660 A2 as well as the DE 198 28 693 A1 such an arrangement is known.

The known devices use so-called superimposed steering systems for the front wheels, in which the transmission ratio between the steering wheel angle and the steering angle can be variably adjusted. In view of the fact that the front wheels can be steered within an angle range of 30°, this is questionable from a safety point of view, since a programming error, for example, can result in a very large steering angle deviation and the driver may no longer be able to compensate for this .

Disclosure of Invention

The above problem is solved by a method with the features of claim 1, by a computer program with the features of claim 8 and by a driver assistance system with the features of claim 9. Advantageous developments result from the dependent claims.

According to the invention

• - Erfassen eines Hindernisses im seitlichen Nahbereich des Kraftfahrzeugs,
• - Ermitteln eines Fahrschlauchs des Kraftfahrzeugs,
• - Ermitteln einer Kollisionsgefahr an Hand des Fahrschlauchs des Kraftfahrzeugs und der Lage des Hindernisses oder der Lage und der Bewegung des Hindernisses und
• - Einstellen eines Lenkwinkels von Hinterrädern des Kraftfahrzeugs bei ermittelter Kollisionsgefahr, um dem Hindernis auszuweichen.

a method is provided for avoiding collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle or for mitigating the consequences of collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle, the method comprising the following steps:

• - Detection of an obstacle in the lateral vicinity of the motor vehicle,
• - determining a driving path of the motor vehicle,
• - Determining a risk of collision based on the driving path of the motor vehicle and the position of the obstacle or the position and the movement of the obstacle and
• - Setting a steering angle of the rear wheels of the motor vehicle when a risk of collision is determined in order to avoid the obstacle.

If it is not possible to drive around the obstacle, i.e. if a collision with the obstacle cannot be avoided, it is proposed to set the steering angle of the rear wheels of the motor vehicle in such a way that a time until the collision, a so-called TTC (time to collision), is maximum , giving the driver more time to react in good time.

It is preferably proposed to navigate the motor vehicle in such a way that the motor vehicle collides with the obstacle in a target impact area on the motor vehicle, i.e. the collision occurs at a point on the side of the motor vehicle at which repair is comparatively cheap, particularly preferably in the area of doors, for example the passenger door and avoiding body parts such as A-pillar, B-pillar, C-pillar or D-pillar. The target impact area can include, for example, an area on the side door, with a hem, ie a distance of a few centimeters from the outer contour of the side door, also being provided to be on the safe side. Applying a steering torque to the rear wheels causes the rear of the vehicle to move away from the obstacle. The steering angle of the rear wheels of the motor vehicle is preferably set in such a way that the obstacle can be avoided as a result. This can be done, for example, in such a way that the rear wheels are turned as far as possible until the obstacle has been passed.

Particularly preferably, avoiding the obstacle is associated with as little steering intervention as possible. According to preferred embodiments of the invention, calculations are therefore provided in order to determine and set an optimum steering angle for the rear wheels of the motor vehicle. The optimal steering angle for the rear wheels of the motor vehicle should be as small as possible and the application of the steering torque to the rear wheels should prevent the motor vehicle from colliding with the obstacle or mitigate the consequences of the collision. It is preferred if, with the optimum steering angle for the rear wheels, the motor vehicle is navigated past the obstacle at a defined distance, for example 5 cm to 50 cm, in particular 10 cm to 20 cm.

It is particularly advantageous to periodically detect the distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle to the motor vehicle, for example at intervals of between 1 ms and 1 s, in particular between 10 ms and 100 ms, for example using ultrasonic sensors , and to regulate the steering angle of the rear wheels of the motor vehicle depending on the distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle to the motor vehicle. Controlling the steering angle is particularly advantageous when the obstacle itself is moving. In such a case, too, it is then possible to navigate the motor vehicle past the obstacle at a defined distance, for example 5 cm to 50 cm, in particular 10 cm to 20 cm.

According to some embodiments, the method may include the step of determining the speed of the motor vehicle. Provision can be made for the rear wheels of the motor vehicle to be activated or executed only below a defined speed, for example below 20 km/h, preferably below 10 km/h, particularly preferably below 6 km/h. In fact, at higher speeds, maneuvers can take place which can be of concern to the safety of surrounding people or the driver, which is intended to be avoided.

Furthermore, it can be provided that the adjustable steering angle of the rear wheels for the evasive maneuver is limited to a maximum value, in particular to a maximum of 3° to 10° or 3° to 5°.

According to the invention, a computer program is also proposed according to which one of the methods described herein is carried out when the computer program is executed on a programmable computer device. The computer program can be, for example, a module for implementing a driver assistance system or a subsystem thereof in a motor vehicle, or an application for driver assistance functions that can be run on a smartphone. The computer program can be stored on a machine-readable storage medium, such as a permanent or rewritable storage medium or associated with a computer device or on a removable CD-ROM, DVD or USB stick. Additionally or alternatively, the computer program may be made available on a computing device, such as a server, for downloading, e.g., over a data network such as the Internet, or a communications link such as a telephone line or wireless connection.

• - eine Umgebungserfassungssensorik, die zur Erfassung des seitlichen Nahbereichs des Kraftfahrzeugs geeignet ist,
• - ein Hinderniserfassungsmodul zur Erfassung eines Hindernisses auf Basis der von der Umgebungserfassungssensorik erfassten Daten,
• - ein Modul zur Ermittlung eines Fahrschlauchs des Kraftfahrzeugs,
• - ein Modul zur Ermittlung einer Kollisionsgefahr des Kraftfahrzeugs mit dem Hindernis an Hand des Fahrschlauchs des Kraftfahrzeugs und der Lage des Hindernisses oder an Hand des Fahrschlauchs des Kraftfahrzeugs und der Lage und der Bewegung des Hindernisses,
• - ein Modul zur Berechnung von optimalen Lenkwinkeln und
• - ein Modul zur Steuerung einer Hinterradlenkung bei ermittelter Kollisionsgefahr des Kraftfahrzeugs mit dem Hindernis, das eingerichtet ist, den Lenkwinkel der Hinterräder des Kraftfahrzeugs derart einzustellen, dass eine Zeit bis zur Kollision maximal ist, falls eine Kollision mit dem Hindernis nicht vermeidbar ist.

Furthermore, a driver assistance system is proposed for avoiding collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle or for mitigating the consequences of collisions of a motor vehicle with an obstacle in a lateral area close to the motor vehicle, comprising:

• - an environment detection sensor system that is suitable for detecting the lateral close range of the motor vehicle,
• - an obstacle detection module for detecting an obstacle on the basis of the data recorded by the environment detection sensor system,
• - a module for determining a driving path of the motor vehicle,
• - a module for determining a risk of collision of the motor vehicle with the obstacle based on the driving path of the motor vehicle and the position of the obstacle or based on the driving path of the motor vehicle and the position and the movement of the obstacle,
• - a module for calculating optimal steering angles and
• - A module for controlling rear-wheel steering when the risk of collision of the motor vehicle with the obstacle is determined, which is set up to adjust the steering angle of the rear wheels of the motor vehicle in such a way that a maximum time until the collision occurs if a collision with the obstacle is unavoidable.

The driver assistance system is suitable for executing the method described above. In principle, the driver assistance system can be combined with other driver assistance systems, in particular with collision avoidance assistants, parking assistants, lane departure warning assistants or reversing warning assistants. In particular, integration into existing SDW systems (so-called side distance warning systems) or FKP systems (flank protection systems) is provided, which warn the driver of obstacles that are located next to the motor vehicle. These systems can easily be supplemented by software changes with the functionality according to the invention.

The driver assistance system can also be based on existing actively controllable rear-wheel steering technology. The driver assistance system preferably uses existing control modules of motor vehicles which have an actively controllable rear wheel steering.

The rear wheels are preferably controlled via a CAN bus or via a Flexray bus.

Advantages of the Invention

The proposed rear-wheel steering makes it possible to avoid an obstacle or to determine the location of the collision of the motor vehicle with the obstacle in such a way that any repair costs on the motor vehicle can be minimized. In contrast, a faulty system execution does not lead to an uncontrollable impairment of the safety of the motor vehicle driver and other road users.

Further exemplary embodiments and advantages of the invention are described below with reference to the drawings.

character list

• 1 eine Situation mit einem Kraftfahrzeug und einem Hindernis in einem seitlichen Nahbereich des Kraftfahrzeugs in Draufsicht,
• 2 die Situation aus 1, wobei das Kraftfahrzeug zu zwei verschiedenen Zeitpunkten dargestellt ist,
• 3 die Situation aus 1, wobei das Kraftfahrzeug zu zwei verschiedenen Zeitpunkten dargestellt ist und ein erfindungsgemäßes Fahrmanöver ausführt,
• 4 eine schematische Darstellung funktionaler Komponenten eines erfindungsgemäßen Fahrassistenzsystems in einem Kraftfahrzeug,
• 5 ein Flussdiagramm, welches Teile des erfindungsgemäßen Verfahrens abbildet.

Show it

• 1 a situation with a motor vehicle and an obstacle in a lateral area close to the motor vehicle in a plan view,
• 2 the situation out 1 , whereby the motor vehicle is shown at two different points in time,
• 3 the situation out 1 , wherein the motor vehicle is shown at two different points in time and executes a driving maneuver according to the invention,
• 4 a schematic representation of functional components of a driver assistance system according to the invention in a motor vehicle,
• 5 a flow chart depicting parts of the method according to the invention.

1 shows a situation with a motor vehicle 1 and an obstacle 2 arranged in a lateral area close to the motor vehicle 1. While the motor vehicle 1 is driving past 3 the obstacle 2, an environment detection sensor system 4, for example optical sensors, ultrasonic sensors, radar sensors, lidar sensors or laser sensors, the obstacle 2, whereupon an SDW system 5 (Side Distance Warning System) determines a distance 18 to the obstacle and, if necessary, its speed, a set steering angle α of the front wheels 6 of the vehicle 1 and the relative speed of the motor vehicle 1 to the obstacle 2 and checks the situation with the obstacle 2 for the existence of a risk of collision. Some SDW systems continue to determine the position of the obstacle 2 even if the obstacle 2 is no longer in the detection range 7 of the sensor 4, as shown. For this purpose, the SDW control unit 5 evaluates, for example, the set steering angle α of the front wheels 6 and distance sensors. In the case shown, the front wheels 6 are turned to the right. Motor vehicle 1 is therefore driving around a curve, and system 5 recognizes that a collision with previously detected obstacle 2 is imminent.

2 the situation out 1 , wherein the motor vehicle 1 is also shown at the time of a collision with the obstacle 2. A first position 8 of the motor vehicle 1 corresponds to that which with reference to 1 was described. A second position 9 of the motor vehicle 1 at the time of the collision with the obstacle 2 was calculated by a collision monitoring module using data from a module for determining a driving path and the position of the obstacle or the position and the speed of the obstacle, as described in more detail with reference to 4 is explained. The module for determining a driving path uses the position 8, the speed and the set steering angles α and β of the front wheels 6 and the rear wheels 14 of the motor vehicle 1 to calculate a driving path 10 of the motor vehicle 1, namely the area covered by the motor vehicle 1 in a defined time . Shown are in this regard example trajectories 11a, 11b of the front corners 12a, 12b of the motor vehicle 1 and trajectories 13a, 13b of the rear wheels 14a, 14b of the motor vehicle 1.

A collision time can be present when the obstacle 2 is located in the calculated driving path 10 of the motor vehicle 1 at a time. In addition, as far as this is possible from the received signals, a movement 15 of the detected obstacle 2 is extrapolated and a potential trajectory is determined. A point in time at which a collision occurs can also occur when, based on the potential trajectory of the obstacle 2, it can be predicted that the obstacle 2 will be located in the calculated driving path 10 of the motor vehicle 1 in the future.

3 shows the situation 1 , wherein the motor vehicle 1 has the functional components of the driver assistance system according to the invention and is designed to carry out the method according to the invention for avoiding collisions or for mitigating the consequences of collisions. 3 shows the situation 1 , wherein the motor vehicle 1 is also shown at a later point in time. A first position 8 of the motor vehicle 1 corresponds to that which with reference to 1 was described. A second position 9' of the motor vehicle 1 was shown at a point in time which corresponds to the point in time of the second position 9 which is shown with reference to FIG 2 was described. A collision with obstacle 2 did not occur. As in particular with regard to the 4 is described, it is provided that a collision monitoring module triggers a module for determining the risk of a collision and the latter calculates a steering angle β of the rear wheels 14 at which a collision can be avoided.

The motor vehicle 1 thus performs an evasive maneuver as shown. The rear wheels 14 are turned in such a way that the rear of the motor vehicle 22 moves away from the obstacle 2 . A motor vehicle pivot point 17 of the steering process with rear-axle steering and possibly with front-axle steering is shifted relative to a motor vehicle pivot point 16 with only front-axle steering. As a result, the motor vehicle 1 drives around the obstacle 2 at a certain distance 23.

Target impact areas 20 , 21 are defined on the motor vehicle 1 on its lateral flank 19 , which include a first target impact area 20 in the front side door and a second target impact area 21 in the rear side door of the motor vehicle 1 .

If the system determines that a collision with the obstacle 1 is unavoidable, the system can calculate the steering angles β of the rear wheels 14 with which the collision on the motor vehicle 1 is steered into the target impact areas 20, 21. Alternatively or additionally, the system can calculate a time to collision (TTC, “time to collision”) for different steering angles β of the rear wheels 14 and determine the angle β or those angles which lead to a maximum time to collision. This gives the driver an opportunity to avoid the obstacle 2 or to bring the vehicle to a standstill before the collision.

4 shows a schematic representation of functional components of a driver assistance system which is designed to carry out the method according to the invention.

The driver assistance system includes an environment detection sensor system 4, which can include optical sensor systems, for example monocular or stereo video cameras, and/or ultrasonic sensors, radar sensors, laser sensors and/or LIDAR sensors. The signals from the environment detection sensor system 4 are received in an input circuit 40 . The input circuit 40 is connected to a bus system 41, for example a CAN bus or a Flexray bus, for data exchange with a data processing device 42. The environment detection sensor system 4 is suitable for detecting at least a lateral area close to a motor vehicle.

The data processing device 42 includes an obstacle detection module 43 which receives and processes signals from the environment detection sensor system 4 . The obstacle detection module 43 is suitable for determining a position and preferably also a speed of the obstacle. Suitable methods for this are known. From the position and the speed of the obstacle, a trajectory of the obstacle can be determined, which can be used to determine the risk of collision.

The data processing device also includes a module 44 for determining a driving path of the motor vehicle. Module 44 for determining a driving path of the motor vehicle processes motor vehicle data, in particular steering angle settings of the front wheels and rear wheels, the current speed of the motor vehicle, odometric data, GPS data, motor vehicle model data such as information on the width and/or length of the body, axle width, wheelbase and/or Center distance, location and position of the side flanks of the motor vehicle. In general, the data on the CAN bus and/or on the Flexray Bus or higher protocols available. The module 44 for determining the driving path of the motor vehicle thus calculates in particular the location and position of the motor vehicle at future points in time.

The data processing device 42 also includes a collision monitoring module 45. The collision monitoring module 45 receives data from the module 44 for determining the driving path of the motor vehicle and data from the obstacle detection module 43, which provides the collision monitoring module 45 with information about the position of the obstacle, in particular the distance of the obstacle from the motor vehicle points in time. The collision monitoring module 45 can in particular include a TTC module, which calculates a time TTC up to an imminent collision with the obstacle. The collision monitoring module 45 can be coupled to other modules that are not shown here, which can cause a driver warning and/or to modules that can bring about automatic braking of the motor vehicle and/or to modules that can change a steering angle of the front wheels of the motor vehicle to avoid the collision with the obstacle.

The data processing device 42 also includes a module 46 for determining a risk of collision. The module 46 for determining the risk of a collision is triggered by the collision monitoring module 45 . As soon as a potential collision has been detected by the collision monitoring module 45, the module 46 for determining the risk of a collision becomes active. It exchanges data with the module 44 for determining the driving path of the motor vehicle and with the obstacle detection module 43, which supplies the module 46 with information about the position and speed of the obstacle, in particular the distance of the obstacle to the motor vehicle at specific times, to determine the risk of collision. The module 46 for determining the risk of collision has the task of calculating for different rear-wheel steering angles whether a collision with the obstacle will occur and/or at which point of the motor vehicle the obstacle will hit. For the calculations, it particularly transfers information about the rear wheel steering angle to the module 44 for calculating the driving path. It has an algorithm which calculates an optimal steering angle for the rear axle under constraints such as target impact areas and maximizing the TTC and which, with reference to the flow chart in 5 is explained in more detail. The module 46 for determining the risk of collision can provide output values for further processing for different rear wheel steering angles, which can include information about whether a collision is taking place or not and can also include a TTC and a point of impact on the motor vehicle.

The data processing device also includes a module 47 for setting a steering angle of the rear wheels of the motor vehicle. The module 47 for adjusting the steering angle of the rear wheels of the motor vehicle receives in particular data from the module 46 for determining the risk of collision. Using this data, the module 47 for setting the steering angle of the rear wheels controls the rear wheels and sets the optimal steering angle of the rear wheels as a reaction to the impending collision. The module 47 for setting the steering angle of the rear wheels can carry out the activation via a data bus, in particular the CAN bus or the Flexray bus.

In particular, the modules can be managed in such a way that the rear-wheel steering can be regulated on the basis of the current distance from the obstacle and a target distance, which makes sense in the case of moving obstacles. In this case, direct communication between the obstacle detection module and the module for determining the risk of a collision is advantageous.

5 shows a flowchart which depicts parts of the method according to the invention, with steps which are carried out in particular by the module for determining the risk of collision. The method is set in motion by a step S0 in which the obstacle is detected in the area close to the side of the motor vehicle.

In a first step S1, a steering angle of the rear wheels is initiated. The initiated steering angle is preferably the maximum possible or maximum permissible steering angle, for example 10°, 5° or 3°. In a second step S2, the driving path to be expected is calculated. In a third step S3, the trajectory of the obstacle can be checked. In a fourth step S4, it is calculated whether a collision with the obstacle is imminent. In the fourth step S4, depending on the result, it is preferably also calculated when and at what location on the motor vehicle a collision takes place or at what distance the obstacle is passed.

If no collision has been calculated in the fourth step S4 and the distance to the obstacle is sufficiently large when passing through, the angle is defined as the current best angle. A termination criterion is checked in a fifth step S5. The termination criterion can, for example, be defined using the angle, ie if sufficient accuracy has been achieved. Alternatively or in addition to this, it can also be considered whether immediate action makes sense.

However, if it is determined in the fourth step S4 that there is a risk of collision at the calculated angle or that the distance at which the obstacle is passed is too small, then the calculated time until the collision hits the point of impact on the motor vehicle is considered to be the best at the moment values set. In the fifth step S5, a check is made as a termination criterion as to whether the TTC is at a maximum and whether a target impact area has been hit.

If the termination criterion is met in the fifth step S5, then in a sixth step S6 in the event of a collision, the angle at which the rear wheels are to be applied, at which the time up to the collision is maximum and a collision takes place in a target impact area, is output as the output of the method in a sixth step S6 , and in the event that no collision takes place, the angle with which the rear wheels are to be applied, at which the collision is avoided with minimal steering intervention, is output.

In a further step S7, the module for adjusting a steering angle of the rear wheels of the motor vehicle adjusts the steering angle of the rear wheels of the motor vehicle in order to avoid the obstacle.

If the termination criterion is not met in the fifth step S5, then in an eighth step S8 a new angle is applied, with which the method is carried out again from the second step, i. H. is iterated. The method can continue to run in the interval nesting method or include successive scanning of the angles with equidistant steps.

In the event of a collision, interval nesting is preferably provided, and in the non-collision case, successive scanning of the possible angles with equidistant steps is preferred, since in the latter case a minimum of the TTC must be found. With interval nesting, the initiated angle is halved and the calculation is performed with the halved angle. If no collision is still detected and the distance to the obstacle is sufficiently large when passing, then the best angle is set to half the value. However, if the risk of collision is affirmed, then the other interval is used. Then the calculation is again performed with a value of the angle that halves the interval and iterated until the termination criterion is met.

The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, within the range specified by the claims, a large number of modifications are possible, which are within the scope of expert action.

Claims (9)

Method for avoiding collisions of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle (1) or for reducing the consequences of a collision of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle ( 1) with the following steps: - detecting (S0) an obstacle (2) in the lateral vicinity of the motor vehicle (1), - determining (S2) a driving path (10) of the motor vehicle (1), - determining (S4) a risk of collision Hand of the driving tube (10) of the motor vehicle (1) and the position of the obstacle (2) or the position and the movement of the obstacle (2) and - setting (S7) a steering angle (β) of rear wheels (14) of the motor vehicle (1 ) When the risk of a collision is determined, in order to avoid the obstacle (2), characterized in that the steering angle (β) of the rear wheels (14) of the motor vehicle (1) is adjusted in such a way that a time up to the collision is a maximum if a collision n with the obstacle (2) is unavoidable. procedure after claim 1 , characterized in that an optimal steering angle (β) for the rear wheels (14) of the motor vehicle (1) is determined, so that the motor vehicle is at a defined distance, for example 5 cm to 50 cm, in particular 10 cm to 20 cm, at the obstacle is navigated past. procedure after claim 1 or 2 , characterized in that a distance (18) of the motor vehicle (1) to the obstacle (2) is detected periodically, for example at intervals of between 1 ms and 1 s, in particular between 10 ms and 100 ms, and the steering angle (β) of the rear wheels (14) of the motor vehicle (1) is regulated. Method according to one of the preceding claims, characterized in that the steering angle (β) of the rear wheels (14) of the motor vehicle (1) is set in such a way that the collision of the motor vehicle (1) with the obstacle (2) occurs in a target impact area (20, 21) on the motor vehicle (1) if a collision with the obstacle (2) cannot be avoided. Method according to one of the preceding claims, characterized in that the rear wheels (14) of the motor vehicle (1) are only activated below a defined speed, in particular below 20 km/h, preferably below 10 km/h, particularly preferably below 6 km/h can be done. Method according to one of the preceding claims, characterized in that the adjustable steering angle (β) of the rear wheels (14) is at most 3° to 10° or 3° to 5°. Method according to one of the preceding claims, characterized in that the rear wheels (14) of the motor vehicle (1) are activated via a CAN bus or via a Flexray bus. Computer program for carrying out one of the methods according to one of Claims 1 until 7 , if the computer program is executed on a programmable computer device. Driving assistance system for avoiding collisions of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle (1) or for reducing the consequences of a collision of a motor vehicle (1) with an obstacle (2) in a lateral area close to the motor vehicle ( 1), comprehensive - an environment detection sensor system (4) which is suitable for detecting the lateral area close to the motor vehicle (1), - an obstacle detection module (43) for detecting an obstacle (2) on the basis of the data detected by the environment detection sensor system (4), - a module (44) for determining a driving path (10) of the motor vehicle (1), - a module (46) for determining a risk of collision of the motor vehicle (1) with the obstacle (2) using the driving path (10) of the motor vehicle (1) and the position of the obstacle or using the driving path (10) of the motor vehicle (1 ) and the position and movement of the obstacle (2), - a module for calculating optimal steering angles and - A module (47) for controlling rear-wheel steering when the risk of collision of the motor vehicle (1) with the obstacle (2) is determined, which is set up to set the steering angle (β) of the rear wheels (14) of the motor vehicle (1) in such a way that a time until collision is maximum if a collision with the obstacle (2) is unavoidable.

Images