METHOD AND DRIVER ASSISTANCE SYSTEM FOR AVOIDING A COLLISION OF A VEHICLE WITH AN OBSTACLE

Abstract

A method for avoiding a collision of a vehicle with an obstacle, using at least one ultrasonic sensor. Reflection points are determined during a movement of the vehicle, the reflection points representing locations at which a signal of an ultrasonic sensor was reflected. The reflection points are combined into contiguous, linearly extending wall sections, a wall section having two ends. Furthermore, it is determined whether an end of a wall section is open or closed. The progression abutting an open end of a wall section is extrapolated, and virtual collision points between the vehicle and the extrapolated progression of the wall sections are ascertained. An initiation of a brake intervention follows if a collision with a virtual collision point is imminent. A driver assistance system including at least one ultrasonic sensor configured to carry out the method, and a vehicle including such a driver assistance system, are also described.

Claims

1-10. (canceled)

11. A method for avoiding a collision of a vehicle with an obstacle, a distance between the vehicle and an obstacle in surroundings of the vehicle being determined using at least one ultrasonic sensor in that the at least one ultrasonic sensor emits signals and receives back echoes of the signal reflected at the obstacle, the method comprising the following steps: a) determining reflection points during a movement of the vehicle, the reflection points representing locations at which a signal of the ultrasonic sensor was reflected; b) combining the reflection points into contiguous, linearly extending wall sections, wherein each of the wall sections have two ends; c) determining whether an end of each of the wall sections is open or closed, the end of each wall section being considered to be closed when the reflection points abutting the end follow a non-linear progression, or when, during further movement of the vehicle, no further reflection points are combined with the end of the wall section, and the end otherwise being considered to be open; d) extrapolating a progression of each the wall sections following each open end; e) ascertaining virtual collision points between the vehicle and the extrapolated progressions of the wall sections; and f) initiating a brake intervention based on a collision with at least one of the virtual collision points being imminent.

12. The method as recited in claim 11, wherein an emergency brake application with maximum deceleration is initiated in step f), when it is necessary to avoid a collision with that at least one of the virtual collision points, or to reduce damage, and when no emergency brake application is necessary yet, initiating a comfortable deceleration of the vehicle using a delay which is smaller than the maximum deceleration of the vehicle.

13. The method as recited in claim 12, wherein the delay for the comfortable braking is selected in such a way that the vehicle is decelerated up to a standstill prior to reaching the at one of the virtual collision points.

14. The method as recited in claim 12, wherein the comfortable deceleration is terminated, and a brake is released again, when the at least one of the virtual collision points responsible for the delay has been dispensed with.

15. The method as recited in claim 11, wherein the non-linear progression according to step c) is a bent curve, which is curved away from a movement direction of the vehicle.

16. The method as recited in claim 11, wherein each of the virtual collision points is present as an intersecting point of a straight line given by the extrapolation of one of the wall sections with a boundary line of a driving path of the vehicle.

17. The method as recited in claim 16, wherein the driving path is present due to an instantaneous driving direction of the vehicle, an instantaneous steering angle of the vehicle, and dimensions of the vehicle.

18. The method as recited in claim 11, wherein steps a) through f) are repeatedly run through during the movement of the vehicle.

19. A driver assistance system for avoiding a collision of a vehicle with an obstacle, the driver assistance system comprising: at least one ultrasonic sensor for determining a distance between the vehicle and an obstacle in surroundings of vehicle; wherein the driver assistance system is configured to: a) determine reflection points during a movement of the vehicle, the reflection points representing locations at which a signal of the ultrasonic sensor was reflected; b) combine the reflection points into contiguous, linearly extending wall sections, wherein each of the wall sections have two ends; c) determine whether an end of each of the wall sections is open or closed, the end of each wall section being considered to be closed when the reflection points abutting the end follow a non-linear progression, or when, during further movement of the vehicle, no further reflection points are combined with the end of the wall section, and the end otherwise being considered to be open; d) extrapolate a progression of each the wall sections following each open end; e) ascertain virtual collision points between the vehicle and the extrapolated progressions of the wall sections; and f) initiate a brake intervention based on a collision with at least one of the virtual collision points being imminent.

20. A vehicle, comprising: a driver assistance system for avoiding a collision of a vehicle with an obstacle, the driver assistance system including: at least one ultrasonic sensor for determining a distance between the vehicle and an obstacle in surroundings of vehicle; wherein the driver assistance system is configured to: a) determine reflection points during a movement of the vehicle, the reflection points representing locations at which a signal of the ultrasonic sensor was reflected; b) combine the reflection points into contiguous, linearly extending wall sections, wherein each of the wall sections have two ends; c) determine whether an end of each of the wall sections is open or closed, the end of each wall section being considered to be closed when the reflection points abutting the end follow a non-linear progression, or when, during further movement of the vehicle, no further reflection points are combined with the end of the wall section, and the end otherwise being considered to be open; d) extrapolate a progression of each the wall sections following each open end; e) ascertain virtual collision points between the vehicle and the extrapolated progressions of the wall sections; and f) initiate a brake intervention based on a collision with at least one of the virtual collision points being imminent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 shows the parallel passing of a stationary obstacle.

[0033] FIG. 2 shows an impending collision with a stationary obstacle.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0034] In the following description of the exemplary embodiments of the present invention, identical elements are denoted by the same reference numerals, a repeated description of these elements in individual cases being dispensed with. The figures only schematically represent the subject matter of the present invention.

[0035] FIG. 1 shows a vehicle 10 including a driver assistance system according to an example embodiment of the present invention, which is moving along the direction marked by reference numeral 36. Based on movement direction 36, the speed and the dimensions of vehicle 10, a driving path is determined, which is delimited by two boundary lines 30.

[0036] In the exemplary embodiment shown in FIG. 1, vehicle 10 has six ultrasonic sensors 12 for monitoring the surroundings of vehicle 10. For this purpose, ultrasonic sensors 12 each emit ultrasonic pulses and receive ultrasonic echoes reflected at objects. In FIG. 1, an obstacle 11 is represented in the form of a stationary vehicle. This obstacle 11 represents an object which reflects signals emitted by ultrasonic sensors 12. For each reflected echo, a distance 18 is determined by vehicle 10 or by the driver assistance system assigned to vehicle 10. If the fields of vision in which ultrasonic sensors 12 are able to detect objects at least partially overlap, it is also possible, with the aid of lateration, to determine the exact position of the point reflecting the ultrasound with respect to vehicle 10. For this purpose, distances 18 measured by the two involved ultrasonic sensors 12 as well as the known distance between the two ultrasonic sensors 12 are required.

[0037] Based on the ascertained sensor data of ultrasonic sensors 12, a surroundings map is created, in which reflection points 14 are entered, which each represent the location at which the respective ultrasonic signal was reflected by obstacle 11. If an exact position determination of a reflection point 14 is not possible, for example because only a single ultrasonic sensor 12 has received a corresponding echo, a progression of reflection points 14 may be created, in which the ascertained distances 18 are plotted as a function of the measuring point in time and/or the route traveled by vehicle 10.

[0038] Based on the progression or based on the created surroundings map, reflection points 14 are now combined into objects, reflection points 14, in particular, being combined into contiguous, linearly extending wall sections 20. In the process, reflection points 14 situated closely together are combined into a wall section 20 in the surroundings map or in the progression. Two reflection points 14 may be considered to be situated closely together when a distance between the two reflection points 14 is below a predefined limiting value.

[0039] The contiguous, linearly extending wall sections 20 arising as a result of the combination of reflection points 14 have two ends. In the example illustrated in FIG. 1, both ends are closed ends 26 since reflection points 14 following closed end 26 in each case do not continue to follow the straight, linear progression of the remaining reflection points 14 of wall section 20, but move further away from vehicle 10.

[0040] Since both ends of wall section 20 are closed, no extrapolation of the further progression of wall sections 20 takes place. Since the two boundary lines 30 which delimit the driving path of vehicle 10 also do not intersect wall section 20, no collision point may be ascertained. No collision is imminent between vehicle 10 and obstacle 11.

[0041] FIG. 2 shows a similar situation as FIG. 1. Vehicle 10 is moving along the direction marked by reference numeral 36, the driving path of vehicle 10 again being delimited by the two boundary lines 30. In contrast to the situation shown in FIG. 1, vehicle 10 is no longer moving in parallel to obstacle 11, but is moving at an angle thereto.

[0042] During the movement of vehicle 10, signals are continuously emitted by ultrasonic sensors 12, and echoes are received back, in each case a distance 18 being again assigned to an echo, and reflection points 14 being determined.

[0043] As may be derived from the representation in FIG. 2, the ascertained reflection points 14 were combined into a wall section 20, which has a closed end 26. The closed end 26 is again characterized in that distance 18 of reflection point 14 following closed end 26 with respect to vehicle 10 has increased, so that the position of reflection point 14, which abuts closed end 26, does not follow a linear progression. Reflection point 14 abutting closed end 26 is not situated on a straight line extending through reflection points 14 which were assigned to wall section 20.

[0044] The other end of wall section 20 is an open end 24 since all previously ascertained reflection points 14 are situated in the vicinity of open end 24 on the straight line which is defined by all reflection points 14 of wall section 20. As a result, an extrapolation is carried out, the further progression of wall section 20 being estimated by an extrapolated straight line 28. Extrapolated straight line 28 intersects one of boundary lines 30 delimiting the driving path of vehicle 10 in the representation of FIG. 2. A virtual collision point 32 arises at the intersecting point. The distance between vehicle 10 and virtual collision point 32 is denoted by reference numeral 34.

[0045] A brake intervention takes place based on the identification of the virtual collision point 32, vehicle 10 preferably being decelerated gently and comfortably. For the comfortable deceleration, the delay is selected in such a way that vehicle 10 comes to a halt just before virtual collision point 32. In the event that the driver of vehicle 10 changes movement direction 36 of vehicle 10 by a steering motion in such a way that virtual collision point 32 is dispensed with, the brake intervention is terminated so that the driving operation of vehicle 10 may be continued without interruption.

[0046] Virtual collision point 32 is advantageously already identified before a reflection point 14, which is situated within the driving path of vehicle 10, has been ascertained using ultrasonic sensors 12. Due to this early identification of virtual collision points 32, a brake intervention may be commenced at an earlier stage, and thus a deceleration may take place with a smaller, comfortable delay.

[0047] If the angle between vehicle 10 and obstacle 11 were flatter, so that virtual collision point 32 is situated further away and outside obstacle 11, vehicle 10 would continue to determine reflection points 14 during the comfortable braking, using its ultrasonic sensors 12, and continue to combine them into wall sections 20. If the end of obstacle 11 were reached during the further course, a non-linear progression of reflection points 14 with respect to a straight line would be ascertained, which extends through reflection points 14 assigned to wall section 20. This would then be interpreted as closed end 26 of wall section 20, so that no determination of an extrapolated straight line 28 takes place, and thus also virtual collision point 32 would be dispensed with. This means that in such a case vehicle 10 would initially decelerate carefully until ultrasonic sensors 12 have identified the end of wall section 20 as closed, and thus have identified the end of obstacle 11. Since an impending collision may then be excluded, vehicle 10 would, in this case, continue its driving operation unimpeded, and the comfortable brake application would be terminated.

[0048] The present invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, a plurality of modifications is possible within the scope of the present invention, which are within the capabilities of those skilled in the art.