Collision warning system

Abstract

Method for avoiding collisions between motor vehicles (1, 2), in which at least one sensor (3) of a motor vehicle (1) determines a distance (a) and / or a relative speed of the motor vehicle (1) to a following motor vehicle (2) and a dangerous driving situation is determined from output signals of the sensor (3), wherein in the event of a dangerous driving situation the motor vehicle (1) issues a warning to the following motor vehicle (2), characterized in that the warning is issued to the following motor vehicle (2) as a numerical value, wherein the numerical value represents an estimated time until the following motor vehicle (2) collides with the motor vehicle (1).

Description

The invention relates to a method and a device for avoiding collisions of motor vehicles, wherein a distance and / or a relative speed of the motor vehicle to a following motor vehicle is determined by at least one sensor of a motor vehicle and a dangerous driving situation is determined from output signals of the sensor.Distance measuring devices for motor vehicles and methods based on their output signals for avoiding collisions of motor vehicles, which determine the distance of a motor vehicle from an obstacle located ahead and output a warning to the driver of the motor vehicle at a critical distance, are sufficiently known. Thus, DE 41 23 056 A1 discloses a distance measuring device for motor vehicles, and DE 41 40 227 A1, DE 43 09 606 A1 and DE 43 26 529 A1 disclose various such methods for avoiding collisions of motor vehicles.Furthermore, DE 102 29 033 A1 discloses a method and a device for detecting a risk of an accident, wherein objects in detection areas both in front of and behind the vehicle are detected by means of distance sensors of a vehicle, distances of the objects in front of and / or behind the vehicle are determined from the distance signals during a journey of the vehicle, and a risk of a collision of the object with an opening driver door of the vehicle is determined when the vehicle is stationary. During the travel of the vehicle, the distance signals are used in a driver assistance and / or safety system sensing the environment, e.g. a distance warning system and / or parking aid system. Furthermore, DE 103 28 755 A1 discloses a system for avoiding too short a distance from a following vehicle to a vehicle driving ahead.All these systems, which are intended to reduce the risk of rear-end collisions, which arise increasingly as a result of the continuous increase in the traffic density and the associated reduction in the distances between the vehicles, warn the driver of the own vehicle or even influence the driving style thereof.It is therefore the object of the present invention to specify an alternative method and an alternative device for avoiding collisions of motor vehicles, as a result of which dangerous driving situations can be avoided.According to the invention, this object is achieved by a method for avoiding collisions of motor vehicles, in which a distance and / or a relative speed of the motor vehicle to a following motor vehicle is determined by at least one sensor of a motor vehicle and a dangerous driving situation is determined from the output signals of the sensor, wherein a warning is output to the following motor vehicle in the case of a dangerous driving situation.According to the invention, this object is furthermore achieved by a device for avoiding collisions of motor vehicles, having at least one sensor which is installed in a motor vehicle and which determines a distance and / or a relative speed of the motor vehicle to a following motor vehicle, and having a warning system which determines a dangerous driving situation from output signals of the sensor, which further comprises a warning device which outputs a warning to the following motor vehicle in accordance with output signals of the warning system.Such a method and such a device for avoiding collisions of motor vehicles have the advantage over the prior art that a dangerous or critical driving situation is more easily alleviated by a warning of the following vehicle, because this allows vehicles which passively come into a dangerous situation to be warned early or a following motor vehicle which generates a dangerous driving situation can be alerted to the danger. Thus, rear-end collisions can be better avoided or their severity can be reduced and the sensitivity to dangerous situations can be increased, since a following motor vehicle, preferably in addition to the driver of the own motor vehicle, is warned of the dangerous driving situation.The dependent claims contain advantageous developments and embodiments of the subject matter of the independent claims 1 and 10.According to an advantageous embodiment, the distance, the relative speed and a relative acceleration between the motor vehicle and the following motor vehicle are evaluated for the determination of a dangerous driving situation. This is preferably effected by the at least one sensor, as a result of which the respective signals are provided particularly quickly.An anticipated time until the following motor vehicle meets the motor vehicle is preferably determined from the distance, the relative speed and the relative acceleration and compared with at least one threshold value for determining a dangerous driving situation. This is preferably done by the warning system. By this combination of the sensor output signals, it is possible, by providing only a threshold value from which the driving situation is classified as critical, to not output any unnecessary warnings in non-critical driving situations. The hazardous state can be classified via a plurality of threshold values and a correspondingly increasing intensity of the warning can be achieved. It is of course also possible to determine a dangerous driving situation from the distance and / or the relative speed and / or the relative acceleration alone or in any combination, in particular also without the determination of an anticipated time until the two vehicles meet.As already indicated above, a dangerous driving situation is preferably divided in a stepped manner into driving situations of different dangerous types, to which respective warnings to the following motor vehicle are assigned. This functionality is also preferably provided by the warning system.A warning is output as a numerical value or, in an advantageous embodiment, optically by means of an pictogram to the following motor vehicle. This is preferably effected via an optical display, which can be effected, for example, as a projection into the rear window of the motor vehicle or the rear-view mirrors of the motor vehicle, so that this projection can be recognized by the following motor vehicle or its driver. It is also possible for a warning to be transmitted as optical signals or radio signals to a corresponding receiver in the following vehicle and to be evaluated by a warning system of the following vehicle if said warning system is equipped accordingly. In this case, the warning system of the following vehicle can warn the driver thereof and / or intervene directly in the driving behavior of the following vehicle, for example by means of a braking operation or an amplification of a braking operation triggered by the driver of the following vehicle. An optically output numerical value can represent, for example, the anticipated time until the vehicles meet or the distance between the vehicles.Alternatively or additionally, a warning is preferably emitted to the following motor vehicle by activating the brake light of the motor vehicle. This activation of the brake light can furthermore preferably take place stepwise. The activation of the brake light is preferably triggered by the warning device. Such a step-by-step activation of the brake light takes place, for example, according to DE 196 24 046 A1, in which a step-by-step activation of the brake light is generated as a function of a deceleration of the vehicle or a brake pedal force of the driver in such a way that braking information is made available in more detailed form for a following vehicle, which braking information can be recorded directly, without great consideration and in particular without learning process using already known knowledge stored under the awareness.Further alternatively or additionally, in an advantageous embodiment, a warning is acoustically emitted to the following motor vehicle, wherein an intensity of the acoustic warning is further preferably selected to be adapted to the dangerous driving situation. This acoustic warning is preferably emitted to the following motor vehicle via an acoustic transducer, such as a horn.Further details, advantages and features of the present invention are evident from the following description with reference to the drawings. The following are shown: FIG. 1 is a plan view of a motor vehicle equipped with a device for avoiding collisions of motor vehicles according to an exemplary embodiment of the invention and a following motor vehicle; and FIG. 2 is a block diagram of a device for avoiding collisions of motor vehicles according to an exemplary embodiment of the invention.FIG. 1 shows a motor vehicle 1 having a device for avoiding collisions of motor vehicles according to an exemplary embodiment of the invention, behind which a following motor vehicle 2 is situated at a distance a. At the rear of the motor vehicle 1, preferably integrated into its bumper, there is at least one distance sensor 3 directed to the rear, with which the distance a to the following vehicle 2 and a differential speed and a differential acceleration between the motor vehicle 1 and the following motor vehicle 2 can be measured. In order to output a warning to the following motor vehicle 2, the motor vehicle 1 comprises a visual display 4, which can consist, for example, of a display panel directed toward the rear or a projector projecting into the rear window of the motor vehicle 1. Furthermore, brake lights 5 and rear-view mirrors 6 of the motor vehicle 1 are provided for signaling warnings.FIG. 2 shows a block diagram of a device for avoiding collisions of motor vehicles according to an exemplary embodiment of the invention. The device comprises the at least one sensor 3 which is also shown in FIG. 1 and is installed in the motor vehicle in a rearward direction and is connected to a warning system 8. Warning system 8 evaluates distance a, the relative speed, and the relative acceleration to the following motor vehicle and triggers a warning in a rapidly approaching following motor vehicle that enters a critical driving situation. In order that no unnecessary warnings are issued in an non-critical driving situation, a threshold can be defined from which the driving situation is classified as critical. The hazardous states can also be further classified so that warnings with correspondingly increasing intensity can be emitted to the following motor vehicle. The threshold from which a critical driving situation is detected is preferably determined from the distance, the differential speed and the differential acceleration of the vehicles, which can be combined to an anticipated time until the vehicles meet. Depending on the sensor 3 used, a critical driving situation can also be determined merely from the distance or the differential speed or the differential acceleration or any combination of two of these three possible output signals.The output signal of the warning system 8, which can also receive input signals from at least one sensor (not shown) directed forwards of the motor vehicle and which can emit a warning to the driver of the motor vehicle in which it is installed as a function of the output signals of these sensors and also as a function of the output signal of the sensor 3 directed backwards, is further conducted to a warning device 9, via which a following motor vehicle is warned. The warning device 9 comprises control electronics 9 awhich receive the output signal of the warning system 8 and output a warning to the following motor vehicle and coordinate with respect to their intensity. The output takes place via a visual display 4 and a rear-facing horn 7, which are contained in the warning device 9, and via brake lights 5 and rear-view mirrors 6 of the motor vehicle, which are activated by the control electronics 9 aand into which warning messages are projected via the control device 9 a, which can take place similarly to the visual display 4. The warning can be made, for example, optically per illuminated pictogram or as a numerical value with the estimated time until the vehicles meet or the distance between the vehicles in rear or outside mirrors projected into the rear window or in the dashboard or acoustically by the rear-facing horn 7 or other sound sources in the rear region of the motor vehicle 1, wherein the intensity of the warning signal can increase with increasing risk, for example by increasing frequency or volume. Independently of this, the brake light can also preferably be activated stepwise in order to warn the approaching vehicle.Generally, the detection of the approaching object can be carried out, for example, by a system similar to a parking aid system for long distances or analogously to a system of a cruise control with distance control or a forward driving-on warning system.The foregoing description of the present invention is for illustrative purposes only and is not intended to limit the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.List of reference characters1 Motor vehicle 2 is the following motor vehicle 3 is the rearward-directed sensor of the motor vehicle 4 is the visual display 5 is the brake lights of the motor vehicle 6 is the rear view mirror of the motor vehicle 7 is the rearward-directed horn of the motor vehicle 8 is the warning system 9 is the warning device 9a is the electronic control unit of the warning device

Claims

Method for avoiding collisions of motor vehicles (1, 2), in which a distance (a) and / or a relative speed of the motor vehicle (1) to a following motor vehicle (2) is determined by at least one sensor (3) of a motor vehicle (1) and a dangerous driving situation is determined from output signals of the sensor (3), wherein a warning is output to the following motor vehicle (2) in the case of a dangerous driving situation, characterized in that the warning is output to the following motor vehicle (2) as a numerical value, wherein the numerical value represents an expected time until the following motor vehicle (2) meets the motor vehicle (1).Method according to Claim 1, characterized in that the distance, the relative speed and a relative acceleration between the motor vehicle (1) and the following motor vehicle (2) are evaluated for the determination of a dangerous driving situation.Method according to Claim 2, characterized in that, in order to determine a dangerous driving situation, the expected time until the following motor vehicle (2) meets the motor vehicle (1) is determined and compared with at least one threshold value.Method according to one of the preceding claims, characterized in that a dangerous driving situation is divided in stages into driving situations which are dangerous in different ways and to which respective warnings to the following motor vehicle (2) are assigned.Method according to one of the preceding claims, characterized in that a warning is emitted to the following motor vehicle (2) by activating the brake light (5) of the motor vehicle (1).Method according to Claim 5, characterized in that the activation of the brake light (5) takes place stepwise.Method according to one of the preceding claims, characterized in that a warning is emitted acoustically to the following motor vehicle (2).Method according to claim 7, characterised in that an intensity of the acoustic warning is selected to be adapted to the dangerous driving situation.Device for avoiding collisions of motor vehicles (1, 2), having at least one sensor (3) which is installed in a motor vehicle (1) and determines a distance (a) and / or a relative speed of the motor vehicle (1) to a following motor vehicle (2), a warning system (8) which determines a dangerous driving situation from output signals of the sensor (3), and a warning device (9) which outputs a warning to the following motor vehicle (2) in accordance with output signals of the warning system (8), characterized in that the warning device (9) comprises a visual display (4) in order to emit the warning as a numerical value to the following motor vehicle (2), wherein the numerical value represents an anticipated time until the following motor vehicle (2) meets the motor vehicle (1).Device according to Claim 9, characterized in that the at least one sensor (3) evaluates the distance (a), the relative speed and a relative acceleration between the motor vehicle (1) and the following motor vehicle (2).Device according to Claim 10, characterized in that the warning system (8) for determining a dangerous driving situation determines the anticipated time until the following motor vehicle (2) meets the motor vehicle (1) and compares it with at least one threshold value.Device according to one of the preceding claims 9 to 11, characterized in that the warning system (8) divides a dangerous driving situation in a stepped manner into driving situations of different dangerous types, to which respective warnings to the following motor vehicle (2) are assigned.Device according to one of the preceding claims 9 to 12, characterized in that the warning device (9) emits a warning to the following motor vehicle (2) by activating the brake light (5) of the motor vehicle (1).Device according to one of the preceding claims 9 to 13, characterized in that the warning device (9) comprises an acoustic transducer (7) in order to emit a warning acoustically to the following motor vehicle (2).

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