DE102013015028A1 - Method for operating a vehicle - Google Patents

Abstract

The invention relates to a method for operating a vehicle (2), wherein a driving tube (F) within which the vehicle (2) is likely to travel on a lane (1) is predicted and a vehicle environment is detected. According to the invention, the driving tube (F) of the vehicle (2) is predicated such that it tapers in the direction of travel (x) with increasing spatial and / or temporal distance from a current vehicle position. A relevance of an object (3) detected in the vehicle environment ahead of the vehicle (2) is determined as a function of the position which the object (3) currently or in the near future occupies or will occupy relative to the travel tube (F), and in dependence the determined relevance of the object (3) is decided whether an automatic initiation of at least one measure for collision avoidance or Kollisionsfolgenmeidung should be allowed. Preferably, in addition, a hysteresis range (H) is determined, which includes the travel tube (F), and the hysteresis range (H) is taken into account in determining the relevance of the detected object (3).

Description

The invention relates to a method for operating a vehicle, wherein a driving tube, within which the vehicle is likely to travel on a lane, is determined and a vehicle environment is detected.

From the DE 10 2007 044 761 A1 For example, a method and an apparatus for determining a travel tube extending along a movement path of a vehicle within which the vehicle is likely to travel on a lane are known. In this case, the travel tube is bounded on both sides of the trajectory of a respective Fahrfahrrandrand. At least one of the driving-route edges and additionally at least one lane information, in particular a lane marking representing the traffic lane and the respective driving-route edge, are determined, by means of which an adapted driving route, in particular an adapted driving-route edge, is determined.

The invention has for its object to provide a comparison with the prior art improved method for operating a vehicle.

The object is achieved by the features specified in claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

A method for operating a vehicle provides that a driving route within which the vehicle is likely to travel on a lane is predicted and a vehicle environment is detected. According to the driving lane is predicted such that it tapers in the direction of travel with increasing spatial and / or temporal distance from a current vehicle position. Furthermore, a relevance of an object detected in the vehicle environment ahead of the vehicle is determined, whereby the determination of the relevance takes place as a function of the position which the object currently occupies relative to the travel tube or in the near future, i. H. after a predetermined time step, will occupy. Depending on the ascertained relevance of the object, it is then decided whether an automatic initiation of at least one measure for collision avoidance or collision consequence reduction should be permitted.

Because the at least one measure is automatically initiated as a function of the ascertained relevance of the object for the vehicle, the risk of a collision of the vehicle with an unprotected road user, in particular a pedestrian, as object can be at least reduced in a particularly advantageous manner.

In addition, by thus determining the relevance of the object for the vehicle, a number of false alarms can be reduced because not every detected object represents a potential collision object for the vehicle.

For realizing the method, only a radar-based detection unit and an image acquisition unit in the form of a mono camera are particularly advantageous.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 schematically a traffic situation of a vehicle on a lane with a front of this pedestrian and

2 schematically another traffic situation with the vehicle and a pedestrian.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a plan view of a lane 1 on which a vehicle 2 drives and the lane 1 crossing pedestrian 3 located.

The vehicle 2 has a radar-based detection unit not shown in more detail and an image detection unit in the form of a mono-camera as a sensor, whose detection areas in front of the vehicle 2 are directed. By means of the detection unit and the mono camera is thus one in front of the vehicle 2 located, so a frontal vehicle environment and can be detected in this objects. The pedestrian 3 , hereinafter as an object 3 referred to, is located frontally to the vehicle 2 on the lane 1 and is detected by the radar-based detection unit and the mono-camera.

By vehicle-detected driving dynamics data, such as in particular a current driving speed of the vehicle 2 yaw rate and / or optically detected curvature and / or acceleration becomes one in the next time interval by the vehicle 2 overrun area of the traffic lane 1 as so-called driving tube F predicted. In this case, the driving path F is determined on the assumption that the detected parameters are constant. First, it is assumed that the yaw rate and the current vehicle speed or the acceleration of the vehicle 2 stay constant.

A width of the driving tube F is slightly wider than the width of the vehicle 2 , wherein the travel tube F tapers from a current vehicle position from a certain temporal and / or spatial distance. This taper or taper results from attached circular segments whose radii are dependent on a current driving speed of the vehicle and derived, for example, from predetermined values of the German Road Construction Directive, according to which a maximum permissible driving speed results from a minimum radius of curvature.

Objects detected in the driving tube F 3 apply initially to the method described below for operating the vehicle 2 , in particular for avoidance with unprotected road users as objects 3 , as relevant.

In addition to the travel tube F, a hysteresis range H is predefined, which surrounds the travel tube F at a predetermined distance, wherein the hysteresis range H is provided, in the case of fluctuations in the driving tube F, for example based on changes in the driving speed, no pronounced jumps in the relevance decision receive. The distance between a circumferential edge of the driving tube F and a peripheral edge of the hysteresis range H is preferably constant. Alternatively, the distance may vary. The driving hose F and the hysteresis area H form a safety area in the probable travel path of the vehicle 2

As described above, the pedestrian is considered an object 3 in front of the vehicle 2 captured, where the object 3 on the lane 1 within the predicted travel line F of the vehicle 2 located. Because the object 3 is located inside the driving tube F, the object becomes 3 for the vehicle 2 classified as relevant. Leaves the object 3 the driving hose F becomes the object 3 only then as no longer relevant to the vehicle 2 classified if it also leaves the hysteresis H range.

As one for the vehicle 2 relevant object 3 can also objects 3 be classified, their position in relation to the vehicle 2 can be predicted based on their direction of movement and the speed of the object for the next time steps.

The sensor system detecting by means of the detected signals of the frontal vehicle environment is next to the longitudinal and lateral position of the object 3 also an absolute and / or relative velocity information in the lateral direction y and the longitudinal direction x can be determined, as in FIG 2 is shown in more detail.

Based on the position of the object 3 and the assumption of a constant object speed, in particular in the case of an object located in the driving tube F 3 a first time period TTD can be determined, after which the object 3 have left the driving hose F.

In addition, a second time period TTA is determined, which describes the time that the object 3 until entry into the driving hose F needed. That is, the second time period TTA describes the time that an object is 3 assuming constant dynamics parameters, such as in particular the object speed required until it penetrates into the driving tube F, for which purpose a distance from the edge of the driving lane, the object speed in the direction of the driving tube F and an object width w _{obj are} taken into account.

mit:

v_y,obj:

Objektgeschwindigkeit in lateraler Richtung y;

w_e:

Breite des Fahrzeuges 2;

w_obj:

Breite des Objektes 3;

x_obj:

Abstand in longitudinaler Richtung x;

y_obj:

Abstand in lateraler Richtung y,

wobei die erste Zeitdauer TTD wie folgt ermittelt wird:

The second time period TTA is determined as follows:

With:

v _{y, obj} :

Object velocity in lateral direction y;

w _e :

Width of the vehicle 2 ;

w _obj :

Width of the object 3 ;

x _obj :

Distance in the longitudinal direction x;

y _obj :

Distance in the lateral direction y,

wherein the first time period TTD is determined as follows:

mit:

l_e,front:

Länge einer Zugmaschine des Fahrzeuges 2;

l_e,back:

Länge eines Anhängers des Fahrzeuges 2;

a_e:

Beschleunigung des Fahrzeuges 2;

Δv:

Relativgeschwindigkeit zwischen dem Fahrzeug 2 und dem Objekt 3 in longitudinaler Richtung x.

A third time t ₁ , the time to the entrance of the vehicle 2 into an object tube O, is determined by:

With:

l _{e, front} :

Length of a tractor of the vehicle 2 ;

l _{e, back} :

Length of a trailer of the vehicle 2 ;

a _e :

Acceleration of the vehicle 2 ;

△ v:

Relative speed between the vehicle 2 and the object 3 in the longitudinal direction x.

In this case, the acceleration is a _{e of} the vehicle 2 read out from the CAN bus.

A fourth time t2, the time the vehicle 2 until it leaves the object hose O is determined as follows:

Furthermore, a fifth time period TTC is determined, according to which the vehicle 2 in the longitudinal direction on the same longitudinal section as the object 3 located. This fifth time period TTC describes the time after which, under the given conditions, a collision between the vehicle 2 and the object 3 entry. The fifth time TTC is determined as follows:

If the value of the ascertained fifth time duration TTC is less than the value of the first time duration TTD, it is assumed that a collision occurs after the third time duration t ₁ when the vehicle enters the vehicle 2 into the object tube O, takes place.

In such a case, a time is determined to which a collision avoidance system or collision avoidance system would automatically have to intervene to avoid the collision with brakes or emergency brakes.

In a first embodiment of the method, it is provided that for system release the objects 3 , in particular pedestrians, are classified as relevant, which are already in the driving tube F of the vehicle 2 are located.

In a second embodiment, in addition, those objects 3 taken into account, the first still in the driving tube F occur. If it is determined that the time until the occurrence of a possible collision with the object 3 , so the fifth time TTC, is infinite, no collision of the vehicle 2 with the object 3 expected and accordingly no system reaction initiated.

In a third execution only objects become 3 taken into account, which are located in the driving tube F, it being assumed that the objects 3 do not move out of the driving tube F. The braking automatically initiated by the system is performed in two stages, the current vehicle speed 2 is performed in a first stage with a comparatively low deceleration moment. In a second stage, the vehicle becomes 2 braked with a maximum possible deceleration torque.

During the time determinations and / or during the automatically initiated braking of the vehicle 2 will be in the vehicle 2 a visual and audible warning is issued, causing the driver of the vehicle 2 about the upcoming automatically performed system response, in particular the gradual braking, ie in particular the emergency braking, is informed.

The vehicle 2 is braked in the first stage of braking with a relatively low deceleration torque, whereby the brake lights of the vehicle by the braking 2 come on. The driver of the vehicle 2 is due to the braking performed in the first stage on the system reaction made aware of at least one of the vehicle 2 Subsequent traffic through the flashing brake lights of the vehicle 2 is warned.

The vehicle 2 is delayed in the first stage of braking, and this small delay can be considered as uncritical for subsequent traffic with respect to a rear-end collision, the subsequent traffic being nevertheless warned by the flashing brake lights.

The delay of the vehicle 2 with the relatively low deceleration torque is performed so long that the driver of the vehicle 2 the possibility has, for example, by steering, independent braking, acceleration and / or pressing a switch to avoid the collision.

By doing that the vehicle 2 braked in two stages, it is possible to initiate the emergency braking comparatively late and still be able to avoid the collision. One from the relevance determination of the detected object 3 The resulting function cascade of the system is shortened, whereby a system response is initiated only after a time, within which the present traffic situation is better predictable. In addition, a collision with an object can also occur 3 , which comparatively late from the sensor of the vehicle 2 was detected or enters the driving tube F, be avoided.

For the execution of the complete cascade the confirmation of the detected signals of the detection units of the sensor system is required. The image capture unit in the form of the mono camera captures the object 3 so that the captured object 3 is assigned to an object class with regard to which the system response is initiated. By means of the detected signals of the radar-based detection unit, it can be determined whether the detected object 3 a drive-over or non-drive-over object 3 is. A drive-over or not passable object 3 is determined on the basis of statistical probabilities and measurement characteristics.

Becomes the object 3 only detected by the mono camera, no delay of the vehicle 2 automatically initiated. Only after plausibility of the detected signals by detected signals of the radar-based detection unit is the two-stage deceleration of the vehicle 2 automatically initiated. In this case, the delay is more intensively performed than when the object 3 early would be detected by both detection units of the sensor.

By means of the method is the protection of unprotected objects 3 , in particular the protection of pedestrians and cyclists, improves and increases, being in the environment of the vehicle 2 be warned at the same time a system intervention. In addition, the driver of the vehicle 2 Intervene at any time and thus initiate measures for collision avoidance, such as evasion, or collision impact reduction. Also, the number of false alarms is reduced to a possible minimum.

LIST OF REFERENCE NUMBERS

1

lane

2

vehicle

3

Pedestrian, object

F

driving tube

H

hysteresis

O

object hose

x

longitudinal direction

y

lateral direction

TTD

first period of time

TTA

second period of time

t ₁

third period of time

t ₂

fourth period of time

TTC

fifth period of time

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007044761 A1 [0002]

Claims (5)

Method for operating a vehicle ( 2 ), wherein a travel tube (F), inside which the vehicle ( 2 ) is highly likely to travel, is predicted and a vehicle environment is detected, characterized in that the travel tube (F) is predicted so that it tapers in the direction of travel (x) with increasing spatial and / or temporal distance from a current vehicle position, that a relevance of one in the vehicle ( 2 ) vehicle environment detected object ( 3 ), whereby the determination of the relevance takes place in dependence on the position which the object ( 3 ) is currently occupying relative to the travel tube (F) or is likely to occupy in the near future, and that depending on the determined relevance of the object ( 3 ) for the vehicle ( 2 ) it is decided whether an automatic initiation of at least one collision avoidance or collision mitigation measure should be allowed. Method according to Claim 1, characterized in that, depending on the instantaneous position of the object ( 3 ) relative to the travel tube (F) of the vehicle ( 2 ) a period of time (TTA) until the object ( 3 ) in the driving tube (F), a period of time (TTD) until leaving the driving tube (F) and / or a period of time (TTC) up to a collision entry of the vehicle ( 2 ) with the object ( 3 ) is or will be determined. A method according to claim 2, characterized in that on the basis of the respectively determined time duration (TTA, TTD, TTC) a latest time for the automatic initiation of emergency braking and / or automatic initiation of at least one warning cascade to avoid collision is determined or will. Method according to claim 2 or 3, characterized in that, when determining that the time duration (TTC) until the collision entry is less than the time duration (TTD) until the object ( 3 ) has left the driving hose (F), a two-stage braking of the vehicle ( 2 ) is initiated automatically, wherein the braking is performed in a first stage with a low deceleration torque and in a second stage with a maximum possible deceleration torque. A method according to claim 4, characterized in that from a time of the automatic initiation of the two-stage braking and / or the warning cascade an optical, audible and / or haptic warning signal at least in the vehicle ( 2 ) will be issued.

Images